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THE

TEXAS JOURNAL

OF

SCIENCE

GENERAL INFORMATION

MEMBERSHIP. — Any person or group engaged in scientific work or interested in the promotion of science is eligible for membership in The Texas Academy of Science. Dues for members are $20.00 annually; student members, $12.00 annually; sustaining members, at least $30.00 in addition to annual dues; life members, at least $400.00 in one payment; patrons, at least $500.00 in one payment; corporate members, $250.00 annually; corporate life members, $2000.00 in one payment. Library subscription rate is $45.00 annually. Payments should be sent to Dr. Michael J. Carlo, P.O. Box 10986, Angelo State University, San Angelo, Texas 76909.

The Texas Journal of Science is a quarterly publication of the Academy and is sent to all members and subscribers. Changes of address and inquiries regarding back issues should be sent to Dr. William J. Clark, Drawer H6, College Station, Texas 77844.

AFFILIATED ORGANIZATIONS Texas Section, American Association of Physics Teachers Texas Section, Mathematical Association of America Texas Section, National Association of Geology Teachers American Association for the Advancement of Science Texas Society of Mammalogists

The Texas Journal of Science (USPS 616740) is published quarterly at Lubbock, Texas U.S.A. Second class postage paid at Post Office, Lubbock, TX 79401. Please send form 3579 and returned copies to Texas Tech Press, Box 4240, Lubbock, TX 79409.

ISSN 0040-4403

THE TEXAS JOURNAL OF SCIENCE

Volume 40, No. 1

February 1988

CONTENTS

Fossil prairie dogs {Cynomys) from Texas. By Walter W Dalquest . 3

Conservation of the Catfish Creek ecosystem: a National Natural Landmark

in eastern Texas. By Ray C. Telfair //. . . . 11

Jim Wells County Unit Road System; a continuing saga of South Texas politics.

By Ross N. Dudney, Jr . 25

The County Unit Road System: another view. By J. D. Phaup . 33

Vector geometry of spheres. By Ali R. Amir-Moez . 43

Fuel weight prediction equations for understory woody plants in eastern Texas.

By Hershel C. Reeves and J. David Lenhart . 49

The immunochemistry of beta-lactosides. By Alfred C. Schram and Javad Paktinat . 55

Pattern of heterochromatic variation and phylogeny in the rodent family Gerbillidae.

By Mazin B. Qumsiyeh . . . 63

New potassium-argon dates of mafic rocks within Big Bend National Park, Texas.

By Dennis E. Schucker and Dennis O. Nelson . . . 71

Corrosion of low-carbon steel in 1.0 M HCl inhibited with octlyamine and quinoline.

By Steven G. Spears, Larry G. Spears, and Joycelyn C. Spears . 79

Diel foraging activity of Solenopsis invicta and two native species of ants (Hymenoptera: Formicidae) in Texas. By David M. Claborn,

Sherman A. Phillips, Jr., and Harlan G. Thorvilson . 93

Are dust particles necessary for rain? By C. Bandy . 101

Sexspecific behavior in greylag geese, Anser anser Linnaeus. By Robert Huber . 107

General Notes

Predation on rufous hummingbird by praying mantid. By Jeanette M. Carignan . Ill

Lasiurus blossevillii (Chiroptera: Vespertilionidae) in Texas.

By Hugh H. Genoways and Robert J. Baker . . . Ill

Record of Cryptotis parva from Brown County, Texas.

By Richard M. Pitts and Michael J. Smolen . 113

Instructions to Authors . 115

THE TEXAS JOURNAL OF SCIENCE EDITORIAL STAFF

Editor:

J. Knox Jones, Jr., Texas Tech University Assistant to the Editor:

Marijane R. Davis, Texas Tech University Associate Editor for Botany:

Chester M. Rowell, Marfa, Texas Associate Editor for Chemistry:

Marvin W. Rowe, Texas A&M University Associate Editor for Computer Science:

Ronald K. Chesser, Texas Tech University Associate Editor for Mathematics and Statistics:

Patrick L. Odell, Baylor University Associate Editor for Physics:

Charles W. Myles, Texas Tech University Editorial Assistants:

Robert R. Hollander, Texas Tech University

Richard W. Manning, Texas Tech University

Scholarly papers in any field of science, technology, or science education will be considered for publication in The Texas Journal of Science. Instructions to authors are published one or more times each year in the Journal on a space-available basis, and also are available from the Editor (The Museum, Box 4499, Texas Tech University, Lubbock, Texas 79409, 806/742-2487, Tex-an 862-2487).

FOSSIL PRAIRIE DOGS {CYNOMYS) FROM TEXAS

Walter W. Dalquest

Department of Biology, Midwestern State University, Wichita Falls, Texas 76308

Abstract. — Five nominal species of fossil prairie dogs have been described. Cynomys hibbardi Eschelman and C. vetus Hibbard are of Blancan age and appear to be distinct from modern taxa. C. sispiza Green belongs to the white-tailed subgenus, Leucocrossuro- mys. C. niobrarius Hay and C. meadensis Hibbard are best considered as related to, if not identical with, the modern black-tailed prairie dog, C. ludovicianus. Isolated lower molars of white-tailed prairie dogs in the proper stages of wear can be separated from those of black-tailed prairie dogs by the divided talonid valley and, in m3, mesolophid extending across the talonid basin anterior to the talonid platform. Prairie dogs of Irvingtonian age from the Gilliland local fauna of Knox County and the Slaton local fauna of Lubbock County, Texas, are of the black-tailed group, referable to C. ludovicianus. Key words: fossil prairie dogs; Cynomys; Texas.

Numerous fragmentary remains of prairie dogs have been recovered or noted in sediments of the Pleistocene Seymour Formation of Knox and Baylor counties, Texas, since the Gilliland local fauna of that formation was reviewed (Hibbard and Dalquest, 1966). Some of these bones, including the most complete specimens, even some found several meters beneath the surface prairie soils, proved to be remains of the living Cynomys ludovicianus (Ord). This species lives in the general area of the fossil deposit today. When such bones were heated to incandescence some smoked, burned, and gave off a strong odor of burning collagen. Workers should be aware that prairie dogs can burrow to surprising depths, even in compact, semiconsolidated sand and gravel, and remains found in such deposits should be regarded with suspicion.

Some prairie dog remains proved to be true fossils and were not affected by heating. Specimens from two sites were found in such context that they were almost certainly the same age as the Gilliland local fauna, {ca. 600,000 years BP). Attempts to identify these fossils led to this brief review of the fossil prairie dogs of Texas.

Extant Cynomys

Living prairie dogs belong to two subgenera — Cynomys, the black¬ tailed prairie dog group, and Leucocrossuromys, the white-tailed group. The subgenus Cynomys includes C. ludovicianus (Ord) and C. mexicanus Merriam. Leucocrossuromys includes C. leucurus Merriam, C. parvidens Allen, and C. gunnisoni (Baird). Only C. ludovicianus occurs in Texas today.

The Texas Journal of Science, Vol. 40, No. 1, February 1988

4

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Nominal Species of Fossil Cynomys

Cynomys niobrarius Hay, 1921, the earliest-named species of fossil prairie dog, comes from the Hay Springs local fauna, Irvingtonian Land Mammal Age, of northern Nebraska. The status of the species is uncertain, and it is rarely mentioned in the literature. The Hay Springs material was collected almost a century ago and has been considered mixed (Kurten and Anderson, 1980).

The holotype of the species is “a thoroughly mineralized fossil” skull of a young prairie dog with the deciduous teeth in place. Hay referred it to the white-tailed group but the teeth and skull are large for that subgenus. Most of the characters listed by Hay (1921) as diagnostic occur in Cynomys ludovicianus (anterior ventral termination of root of zygoma opposite Ml, broad groove in front of anterior root of zygomatic arch, sharp ridge along middle of palate) as well as C. leucurus, but are better developed in the larger C. ludovicianus. An exception is the greater angle of contact of the dorsal anterior border of the root of the zygoma. Although this is somewhat variable in young C. ludovicianus and C. leucurus, I found no C. leucurus with the angle so close to 90 degrees as in C. ludovicianus. Nevertheless, C. niobrarius probably is best referred to Cynomys cf. ludovicianus, but whether it represents a valid species of Irvingtonian or later age remains to be determined.

Cynomys vetus Hibbard, 1942, was described from parts of a skull, including the palate, from Jewell County, Kansas. The specimen was not associated with a fauna but has been considered to be of late Blancan age (Eschelman, 1975). Most writers have agreed that this is a distinct species but few diagnostic characters other than size are present in upper dentitions of prairie dogs.

Cynomys meadensis Hibbard, 1956, was based on associated first and second lower molars of a young animal found with fossils of the late Blancan Deer Park local fauna of southwestern Kansas. The description is brief, the species diagnosed by “a small, round conulid rather than a transverse mesolophid on the lingual side of the talonid basin.” The conulids figured are typical of the molars of C. ludovicianus, although small mesolophids often occur in this species. The molars of the holotype can be matched by unworn teeth of most young C. ludovicianus. The teeth are rather but not excessively small (ml, 3.0 mm long; m2, 3.3 mm long). Kurten and Anderson (1980) cited a personal communication from L. Martin stating that the holotype is thought to be intrusive from a younger age.

Cynomys sispiza Green, 1960, from South Dakota, was originally thought to be from a Tertiary deposit but later (Green, 1963) determined to be from Pleistocene sand. The figure of the lower dentition of the holotype shows the m3 to have the talonid valley closed with a mesolophid reaching completely across the talonid basin, and m2 with

FOSSIL PRAIRIE DOGS OF TEXAS

5

the talonid basin divided transversely by a mesolophid. These are characters of Cynomys (Leucocrossuromys). C. sispiza may be a specimen of Pleistocene Cynomys leucurus.

Cynomys hibbardi Eschelman, 1975, is a small, primitive prairie dog. The lower jaw of the holotype with almost unworn ml -m3 is from the late Blancan White Rock local fauna of Republic County, Kansas. C. vetus was found in the same area, suggesting that the two species may have been sympatric.

Of the five nominal species of prairie dogs, Cynomys hibbardi and C vetus probably are valid, extinct species. C. sispiza may be a synonym of C leucurus, and C. niobrarius and C. meadensis may be synonyms of C. ludovicianus.

Identification of Subgenera

Black-tailed prairie dogs differ from white-tails in size, color, cranial and dental characters, and habits. Lower jaws of black-tails can be separated from those of white-tails by their relatively large size, heavy structure, stout processes, large articular surfaces, and large muscle scars. These criteria, however, rarely can be used for fossil material. Parts preserved as fossils usually are isolated teeth, fragmentary lower jaws lacking ascending rami and processes, fragmentary maxillaries or, rarely, a palate. Identification of fossils to subgenus requires a study of characters of the dentition of the two subgenera.

No qualitative characters were found in the upper dentitions that serve to separate Cynomys from Leucocrossuromys. Details of enamel pattern vary individually and with tooth wear. There are reliable characters in the lower dentitions (Fig. 1), especially in m2 and m3, but these are discernible only when specimens of similar age are compared.

Lower jaws of Recent prairie dogs (50 Cynomys ludovicianus, 20 C. gunnisoni) were separated into three age classes: stage 1, young animals with the ectolophid of m3 a sharp-edged ridge, not (or barely) worn through; stage 2, with the ectolophid worn through to expose the dentine as a narrow lake but the posterior part of the talonid platform still showing some enamel folds and denticulations; stage 3, with the ectolophid broadly worn, the talonid platform worn flat or the entire talonid basin worn to a round-bottomed depression. Specimens in wear stage 3 cannot be identified to subgenus by their dentitions. The most reliable and readily seen characters are found in m3.

Semken (1966) observed that in 90 percent of specimens he examined the talonid valley of the m3 in the black-tailed prairie dogs was an open trough, but in 90 percent of the white-tails the valley was blocked by a stylid that divided it into two parts. Study of Semken’s character and related details shows that it is even more discriminate than he believed.

6

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Figure 1. Lower second and third molars of prairie dogs. Top row, Cynomys ludovicianus: A, almost unworn teeth (MWSU 1409); B, lightly worn teeth (MWSU 3035). In this species the talonid valley (tv) is not divided and the talonid platform (tp) is not limited by a mesolophid (ml). Lower row, Cynomys gunnisoni (TTU 39643), almost unworn teeth (C); Cynomys leucurus (MWSU 1731), teeth slightly worn (D). In white-tailed prairie dogs, the talonid valley is divided and the talonid platform is confined anteriorly by a mesolophid. The transverse valley at the anterior ends of each tooth is the trigonid basin (tb); the labial margin of the tooth is the ectolophid (el). Anterior to left; lingual to top.

In the black-tailed prairie dog, the m3 in wear stage 1 usually has the ectolophid gently curved. The talonid valley (basin trench of Black, 1963) follows the lingual margin of the ectolophid but its ends are deflected lingually by the protoconid and hypoconid, giving the valley a flattened “W” shape. The talonid platform is an elevated structure lingual to the talonid valley; its surface enamel is complexly and variably wrinkled and denticulate. The labial margin of the platform is elevated as a denticulated lophid that forms the internal margin of the talonid valley. The talonid platform is irregular in shape with its internal edge the lingual margin of the tooth. There is no mesolophid limiting the enamel structures of the platform.

In wear stage 2, the dentine of the ectolophid is exposed as a narrow, isolated, enamel lake. The enamel of the lingual margin of the ectolophid passes about the ends of the valley to join the lophid bordering the valley lingually, forming a deep enamel lake. At this stage, in approximately 25 percent of the teeth, the valley is shallowest at or near its center, occasionally so shallow that when the enamel is worn through the valley

FOSSIL PRAIRIE DOGS OF TEXAS

7

is divided into two parts. In most instances, the valley is not (or is only slightly) shallower at the middle, and the valley persists as a single trough until wear stage 3.

In the white-tailed group, m3 usually (90 percent) has a small medial cusp, the mesostylid, on the internal slope of the ectolophid. (A mesostylid, if present in the black-tailed m3, is on the top, not the side, of the ectolophid.) The talonid valley is blocked by the mesostylid, separating the talonid basin into two deep pits. This separation, at stage 1, readily identifies the tooth as that of a white-tail. From the mesostylid, a narrow (straight or convoluted) mesolophid extends lingually or anterolingually across to the lingual edge of the tooth. The mesolophid limits the talonid platform to a somewhat triangular area. In rare white¬ tailed m3’s in which mesostylids fail to develop, the mesolophids that limit the talonid platform to a triangular area are present and serve to identify the teeth as white-tail.

At wear stage 2, the talonid valley is divided into two closed enamel lakes. The posterior part of the talonid platform wears away more swiftly than the anterior part (at wear stage 3, the platform becomes a deep, rounded pit). The mesolophid usually is still discernible in wear stage 2.

The enamel structures of the surfaces of ml and m2 are worn away before those of m3, and on ml appear to be more transient than on m2. The second lower molar is larger than ml and more readily identifiable than is ml. However, the two teeth and their characters are similar.

In the black-tailed prairie dog in stage 1, the talonid basins of ml and m2 are deep, round-bottomed depressions. One, two, rarely three, small, pointed conulids or a short mesolophid with vertical ends are present at the bottom of the basin. On rare individuals, the lophid is a bit longer but it does not meet the ectolophid labially or extend to the lingual margin of the tooth. Even into stage 2, the talonid basin is a single broad pit posterior to the trigonid basin.

In the white-tails, the talonid basin of ml and m2 in stage 1 is crossed by a shallow, straight mesolophid. The tooth pattern consists of three closed pits: the anterior trigonid basin, and an isolated large medial and a smaller posterior part of the talonid basin.

Earlier Pleistocene Prairie Dogs of Texas

Cynomys was in existence in the late Blancan (Eschelman, 1975) and must have evolved from Spermophilus stock in the late Tertiary (Bryant, 1945). The oldest records for Texas, however, date from the Irvingtonian Land Mammal Age, Seymour Formation, Gilliland local fauna, of Knox and Baylor counties. Stratigraphically, the specimens come from beneath the Type O Pearlette volcanic ash, dated from a number of places on the Great Plains at 600,000 years before present (Izett et al., 1971). A prairie dog astragalus, four upper cheekteeth, and a lower m2 were recovered

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

from a disintegrating carnivore coprolite eroding from an undisturbed clay bed in the Seymour Formation, north of Red Springs, Baylor County. A quarry on the Burnett Ranch, Knox County, has yielded numerous remains of small mammals, all representative of the Cudahay- type Gilliland local fauna. Among the fossils here recovered are a worn upper Cynomys molar, part of another, and part of a lower molar. Fossil prairie dog material from these two sites is certainly the same age as other mammals of the Gilliland local fauna and not intrusive from later ages.

Number 12225 (Midwestern State University Collection of Fossil Vertebrates), Burnett Ranch, consists of the external half of m3 in wear stage 1, broken anteroposteriorly along the bottom of the talonid valley. The ectolophid is sharp and the fracture shows that the talonid valley was deep along its entire length. No mesostylid was present and the tooth is of the black-tail type.

Of the teeth from Red Springs (12227), the m2 is in wear stage 1. The talonid basin possess a short lophid, distinctly shorter than the mesolophids found in the m2’s of white-tailed prairie dogs. These teeth also seem to be of the black-tailed type.

The Slaton Quarry local fauna (Meade, 1942, 1952; Dalquest, 1967) is also of Irvingtonian age, probably younger than the Gilliland local fauna but not as young as Dalquest (1967) suggested. The presence of the water rat {Neofiber leonardi) in the Slaton deposit, and its presumed ancestor. Proneofiber guildayi, in the Gilliland fauna, led to estimation of Illinoian glacial age. Yarmouthian interglacial or late Kansan glacial age seems more likely (Hibbard and Dalquest, 1973). All records of Neofiber leonardi are of middle Pleistocene age (Frazier, 1977).

The Slaton collection is rich in prairie dog material. Three maxillaries with P4-M3, three lower jaws with p4-m3, several upper and lower jaw fragments with teeth, and about 50 isolated teeth, are included. When I (Dalquest, 1967) referred these specimens to Cynomys vetus I was not aware of Semken’s (1966) characters for separating white-tailed from black-tailed prairie dogs, or of the changes that occur in prairie dog teeth with wear. After being unavailable for many years, the Slaton collection has been recovered and the Cynomys specimens reexamined.

The Slaton prairie dog fossils consist entirely of old individuals. There are no lower molars in wear stage 1 and only five in stage 2. The remainder, including those in jaws, are in stage 3. The small size of the lower cheekteeth results from excessive age and wear. The teeth are similar in size to cheekteeth of Cynomys ludovicianus in wear stage 3.

The single m3 has the talonid valley undivided. The four first and second lower molars do not have the talonid basin transversely divided, and two show the bases of small, rounded stylids. The characters of these

FOSSIL PRAIRIE DOGS OF TEXAS

9

teeth are of the subgenus Cynomys, not Leucocrossuromys. They are not white-tails and I erred in referring them to Cynomys vetus in 1967.

Late Pleistocene Prairie Dogs

The prairie dogs of the medial Pleistocene (Irvingtonian age) Gilliland and Slaton local faunas are best regarded as Cynomys cf. ludovicianus until fossils adequate for specific identification are discovered. Cynomys ludovicianus has been reported from numerous local faunas of Rancholabrean age in Texas. The Ingleside local fauna (Lundelius, 1972), from near Corpus Christi, on the Gulf Coast, includes Cynomys ludovicianus, showing that the black-tailed prairie dog extended to the Gulf of Mexico in the later Pleistocene. Records from numerous caves on the Edwards Plateau (for example, Evans, 1961; Dalquest et al., 1969) show that the species was widespread through the Hill Country in the late Wisconsin glacial age. In the later Pleistocene, the black-tail prairie dog must have occupied almost all of Texas west of the Balcones Fault Zone (as defined by Schmidly, 1983), including areas where it has not lived in historic times.

Semken’s (1966) record of Cynomys cf. gunnisoni and C. ludovicianus together in the Sandahl local fauna shows that in the Pleistocene a kind of white-tailed prairie dog lived in Kansas east of the present range of white-tails. Ayer (1936) listed Cynomys gunnisoni from late Pleistocene cave faunas from the Guadalupe Mountains of Texas. Other cave local faunas from the Guadalupe Mountains (Schultz and Howard, 1935) and nearby (Dry Cave, Eddy County, New Mexico — Harris, 1977; Fowlkes Cave, Culberson County, Texas— Dalquest and Stangl, 1984) have yielded Cynomys ludovicianus. The Fowlkes Cave specimens have been reexamined and certainly belong to C. ludovicianus. I have not seen the materials referred to C. gunnisoni but, if they truly are C. gunnisoni they are the only records of that species from Texas.

Acknowledgments

This study was supported by a grant from Midwestern State University. Specimens of Cynomys parvidens were made available through the kindness of Robert Baker and Robert Owen, The Museum, Texas Tech University. Fred Stangl and Rose Carpenter aided in field and laboratory work. The drawings were made by Margaret Stevens.

Literature Cited

Ayer, M. Y. 1936. The archeological and faunal material from Williams Cave, Guadalupe Mountains, Texas. Proc. Acad. Nat. Sci. Philadelphia, 88:599-618.

Black, C. C. 1963. A Review of the North American Tertiary Sciuridae. Bull. Mus. Comp. Zook, 130:111-248, 22 pis.

Bryant, M. D. 1945. Phylogeny of Nearctic Sciuridae. Amer. Midland Nat., 33:257-390.

10

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Dalquest, W. W. 1967. Mammals of the Pleistocene Slaton local fauna. Southwestern Nat., 12:1-30.

Dalquest, W. W., E. Roth, and F. Judd. 1969. The mammal fauna of Schultz Cave, Edwards County, Texas. Bull. Florida State Mus., 13:206-276.

Dalquest, W. W., and F. B. Stangl, Jr. 1984. Late Pleistocene and Recent mammals from Fowlkes Cave, Culberson County, Texas. Pp. 432-445, in Contributions in Quaternary vertebrate paleontology: a volume in memorial to John Guilday (H. H. Genoways and M. R. Dawson, eds.). Spec. Publ. Carnegie Mus. Nat. Hist., 8:1-538.

Eschelman, R. E. 1975. Geology and paleontology of the early Pleistocene (late Blancan) White Rock fauna from north-central Kansas. Univ. Michigan Papers Paleo., 13:1-60.

Evans, G. L. 1961. The Freisenhahn Cave. Bull. Texas Mem. Mus., 2:1-22.

Frazier, M. F. 1977. New records of Neofiber leonardi (Rodentia, Cricetidae) and the paleoecology of the genus. J. Mamm., 58:368-373.

Green, M. 1963. Some late Pleistocene rodents from South Dakota. J. Paleo., 37:688- 690.

Harris, A. H. 1977. Wisconsin Age environments in the northern Chihuahuan Desert: evidence from higher vertebrates. Pp. 23-52, in Transactions of the symposium on the biological resources of the Chihuahuan Desert region. United States and Mexico (R. H. Wauer and D. H. Riskind, eds.), Nat. Park Serv. Trans. Proc., 3:1-658.

Hay, O. P. 1921. Description of species of Pleistocene Vertebrata, types or specimens of most of which are preserved in the United States National Museum. Proc. U.S. Nat. Mus., 59:599-642.

Hibbard, C. W., and W. W. Dalquest. 1966. Fossils from the Seymour Formation of Knox and Baylor counties, Texas, and their bearing on the late Kansan climate of that region. Contrib. Mus. Paleo., Univ. Michigan, 21:1-66.

- . 1973. Proneofiber, a new genus of vole (Cricetidae: Rodentia) from the

Pleistocene Seymour Formation of Texas, and its evolutionary and stratigraphic significance. J. Quart. Res., 3:269-274.

Izett, G. A., R. W. Wilcox, J. D. Obradovich, and R. L. Reynolds. 1971. Evidence for two Pearlette-like ash beds in Nebraska and adjoining areas. Geol. Soc. Amer., Abst. with Prog., 3:657.

Kurten, B., and E. Anderson. 1980. Pleistocene mammals of North America. Columbia Univ. Press., New York, 442 pp.

Lundelius, E. L. 1972. Fossil vertebrates from the late Pleistocene Ingleside fauna, San Patricio County, Texas. Bur. Eco. Geol., Univ. Texas, Rept. Invest., 77:1-74.

Meade, G. E. 1942. A new species of Capromeryx from the Pleistocene of west Texas. Bull. Texas Archeo. Paleo. Soc., 14:88-96.

- . 1952. The water rat in the Pleistocene of Texas. J. Mamm., 33:87-89.

Semken, H. A., Jr. 1966. Stratigraphy and paleontology of the McPherson Equus beds (Sandahl local fauna), McPherson County, Kansas. Contrib. Mus. Paleo., Univ. Michigan, 20:121-178.

Schmidly, D. J. 1983. Texas mammals east of the Balcones Fault Zone. Texas A&M Univ. Press, College Station, xviii + 400 pp.

Schultz, C. B., and E. B. Howard. 1935. The fauna of Burnett Cave, Guadalupe Mountains, New Mexico. Proc. Acad. Nat. Sci. Philadelphia, 87:273-298.

CONSERVATION OF THE CATFISH CREEK ECOSYSTEM: A NATIONAL NATURAL LANDMARK IN EASTERN TEXAS

Ray C. Telfair II

Texas Parks and Wildlife Department, Management and Research Station, Route 10, Box 1043, Tyler, Texas 75707

Abstract. — On 1 June, 1983, the United States Department of the Interior proposed that Catfish Creek become a National Natural Landmark based on a recommendation from the National Park Service. The creek was so designated and is included on the National Registry of Natural Landmarks. Most of the designated area is within, or borders, the Engeling Wildlife Management Area. This paper documents the significance of the Catfish Creek ecosystem as representative of one of the few remaining relatively undisturbed spring- fed riparian wetlands of the western Gulf Plain natural region.

The background data base includes historical and recent documentation of land use, vegetation, and wildlife. Significant values are identified. Current status and future trends are discussed including land and water conversion and rare or unique wetlands, flora, and fauna. Management needs and recommendations are presented. Key words: conservation; Catfish Creek; national natural landmark; eastern Texas.

Catfish Creek is an eastern tributary in the upper middle basin of the Trinity River. Its headwaters are in south-central Henderson County, Texas. Most of the creek flows through northwestern Anderson County to its southwestern confluence with the Trinity River on the boundary of Freestone County. The Catfish Creek ecosystem covers 1805 hectares for a distance of about 32 kilometers. Twenty-four branches and small creeks maintain a free-flowing meandering bottomland. Several small impound¬ ments are located on the reach in Henderson County. Diverse wetland habitats include forest, marshes, swamps, bogs, and springs (Figs. 1-2).

Most of this ecosystem is in bottomland hardwood forest and wetlands historically used for timber production and grazing. The system is flooded annually and is unsuited for most cultivation, housing sites, or industry. About half of the ecosystem is associated with the Engeling Wildlife Management Area (4428 hectares), owned and managed by the Texas Parks and Wildlife Department. The initial tract was acquired in

1950. The last addition was made in 1961. The area was named in honor of Gus A. Engeling, a wildlife biologist who was killed by a poacher in

1951. The tract was selected as an area on which to conduct long-term wildlife management research and demonstration of results.

Background Data

History of the Derden Wildlife Management Area (renamed the Engeling Wildlife Management Area) was documented by Engeling (1951). Most of the information was obtained by personal interviews of senior citizens in nearby communities. Also, information

The Texas Journal of Science, Vol. 40, No. 1, February 1988

12

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Figure 1. Location of Catfish Creek ecosystem in relation to the Trinity River system, Dallas-Fort Worth Metroplex, and reservoirs (impounded, under construction, and potential).

was obtained from records in libraries in Palestine. By this method, history of land use, vegetation, and wildlife was traced since the time of the earliest settlers (about 1830).

Vegetation was inventoried by Teer (1952a). A vegetation type-map was prepared and a plant collection was assembled. The plant collection totaled 240 species consisting of 56 woody species, 25 grasses, and 159 forbs. Wildlife also was inventoried by Teer (1952b). Efforts were restricted to mammals and birds. Techniques included sight records, observations of signs, trapping, calls, and simple census methods. Documentation was secured for most common wildlife species of the area. Included were: white-tailed deer {Odocoileus virginianus), gray and fox squirrels (Sciurus carolinensis and S. niger), eastern cottontails and swamp rabbits {Sylvilagus floridanus and S. aquaticus), nine-banded armadillos (Dasypus novemcinctus), wild turkeys (Meleagris gallopavo), northern bobwhites {Colinus virginianus), nine species of furbearers, six species of waterfowl, and 58 species of songbirds.

From January 1972 through May 1973, Lodwick (1975) studied the net aerial primary production of the vascular plants of Andrew’s Bog, a 104-hectare bog site on the Engeling Area. A tentative checklist of vegetation and an historical chronicle of the area were prepared by Veteto et al. (1976) and Davis and Veteto (1978). The vegetation list was based upon herbarium specimens and field identifications. The list included 471 species — 83 woody plants, 80 grasses, 46 legumes, 63 composite forbs, 172 other forbs, and 27 sedges, rushes, and bulrushes.

CATFISH CREEK ECOSYSTEM, TEXAS

13

Tentative checklists of vertebrates were prepared for freshwater fishes (Telfair, 1977), amphibians and reptiles (Telfair and Thomas, 1974), birds (Telfair and Arnold, 1974), and mammals (Telfair and Martin, 1974). These lists were based upon limited creel censuses, museum specimens, and field collections. Sight records, distribution maps, and checklists from adjacent counties were also major sources of information. Total species listed were: 88 fishes; 10 sirens, salamanders, newts, and mudpuppies; 18 toads and frogs; 15 turtles; one alligator; 12 lizards; 30 snakes; 194 birds; and 45 mammals.

In June and early July of 1982 to 1984, I taught a university-level field studies course at the Engeling Wildlife Management Area. Major projects involved collecting, identifying, and preserving voucher specimens of the flora and fauna to expand and verify the checklists that were published from 1974 to 1978. Other field trips were conducted in the autumn, winter, and spring of 1982 to 1985. As a result of these efforts, the following results were obtained.

Emphasis was placed upon wetland and aquatic plants. Also in the period 1982 to 1984, many plants were collected and identified by Ms. Mary E. May, Research Assistant, Stephen F. Austin State University, during a study of the food habits of feral hogs {Sus scrofa) on the area. Currently, verified vascular plants number 676 species — 112 trees, shrubs, and woody vines, 130 grasses, 57 legumes, 85 composite forbs, 222 other forbs, and 70 wetland and aquatic plants.

Soils in the bottomland along Catfish Creek are moderately permeable, shallow, gray- brown, sandy loams. As a result, mature trees are subject to wind-throw. In the summer of 1984, my students and I (Telfair et al., 1984) determined the number of wind-thrown, den, and snag trees. Eleven randomly-selected sites of 0.04 hectare were chosen for analysis. Per 0.4 hectare, there were 4.5 wind-thrown trees (x DBH = 41.1 centimeters), two den trees (x DBH = 47.5 centimeters), and two snags (x DBH = 39.1 centimeters). There was an average of 27 trees per sample site with only 12 percent being greater than 35 centimeters DBH. Thus, wind-thrown, den, and snag trees were larger than other trees by an average of 3.0 centimeters DBH. Percentages of occurrence were wind-thrown trees (17 percent), den trees (seven percent), and snags (seven percent).

The scarcity of mature trees larger than 35 centimeters DBH has been seriously considered by Mr. Carl D. Frentress (personal communication). Wildlife Biologist, Texas Parks and Wildlife Department. He offered the following hypothesis. Large, mature trees probably have not been common in the Catfish Creek bottomland. Most large-diameter trees have sustained some reduction of crown mass from lightning strike or break-out of the crown. Such trees generally are shorter than their neighbors, especially in relation to diameter. This situation reduces the mechanical advantage of leverage resulting from wind resistance of the crown. Thus, tall, healthy, bottomland trees are especially susceptible to wind-throw. Shorter trees have a better chance of standing longer, and, thus, have more time to increase in diameter. Furthermore, wind-throw may be more a function of shallow root systems than physical characteristics of soils. Shallow root systems may be the result of a predominantly near-surface water table.

Fishes were collected by use of leader-wing traps, hook and line, electroshocking boats, seining, and rotenone treatment. This was done in cooperation with Mr. Charles R. Inman, Inland Fisheries Biologist, Texas Parks and Wildlife Department. Representative samples of each species and age class were preserved for the teaching collection of the Department of Wildlife and Fisheries Sciences, Texas A&M University. The number of verified fish species is 48 of a possible 88 species. (54 percent).

Amphibians and reptiles were collected by cruising roads, searching habitats, drift fences, seining, fish and turtle traps, hook and line, and rotenone treatment. Each species was photographed and specimens were preserved for the Texas Cooperative Wildlife Collection of the Department of Wildlife and Fisheries Sciences, Texas A&M University. The number of verified species or subspecies in comparison to those that possibly may occur on the area were: sirens, salamanders, newts, and mudpuppies (one of 10, 10 percent); toads and frogs (10 of 19, 53 percent); turtles (10 of 14, 71 percent); alligator; lizards (five of 12, 42 percent);

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Figure 2. The Catfish Creek ecosystem in relation to the vegetation cover type map of the Engeling Wildlife Management Area, Anderson Co., Texas. The map is modified from that drawn by Mr. Greg Yarrow, graduate student, Stephen F. Austin Stte University. Beaver ponds are those located by Mr. Yarrow and Ms. Julie A. Hogan, Wildlife Biologist, Engeling Wildlife Management Area. The dark, heavy line separates upland from bottomland vegetation types.

CATFISH CREEK ECOSYSTEM, TEXAS

15

and snakes (17 of 33, 51 percent). Therefore, the total verified species or subspecies of amphibians and reptiles was 44 of a possible 89 (44 percent).

Migratory and breeding birds were verified by sight records, collecting, hunter kills of waterfowl, banding of nestlings, and banding juveniles and adults trapped in mist nets. The total numbers of bird species that pass through the area or are breeding, winter, or permanent residents there include 128 migrants, 82 breeding residents, 107 winter residents, and 43 permanent residents.

Mammals were verified by sight records, live-trapping, spot-lighting, mist-netting of bats, predator calling, and scent analysis of tracks (Strapper, 1984). The number of verified species in comparison to species that possibly may occur in the area are 34 of a possible 48 species (71 percent).

On 18-20 April 1986, the Texas Herpetological Society held an annual spring meeting at the Engeling Wildlife Management Area, Amphibians and reptiles were collected by road- cruising, habitat-searching, seining, and turtle trapping. This effort may have completed the list of verified species and subspecies in comparison with those that possibly may occur on the area: sirens, salamanders, newts, and mudpuppies (four of 10, 40 percent); toads and frogs (13 of 19, 68 percent); turtles (11 of 14, 78 percent); alligator; lizards (nine of 12, 75 percent); and snakes (23 of 33, 70 percent). Therefore, the total verified taxa of amphibians and reptiles was 61 of a possible 89 (68 percent).

Significance

Land Use

According to an early settler: “Bottomlands were free of underbrush and cattle and deer could be seen for several hundred yards. Wagons could be driven to Catfish Creek, which had clean, hard banks at almost any point. Wildlife was present in great abundance” (Davis and Veteto, 1978).

Catfish Creek and its spring-fed branches furnished ideal camp and village sites for several tribes of American Indians. Apparently, the area was used by roving bison hunters from the west (Comanches, Tonkawas, and Wacos) and sedentary farmers of the east (Caddoes, Kickapoos, lonis, Keechis, Neches, and Cherokees). Farming probably did not seriously degrade the soil. However, hunting expeditions and burning practices did influence vegetation and wildlife. Fire was used to drive game and, in late winter, selected areas were burned to assure tender spring grass for horses. These Indians were little disturbed until 1830. Land surveying began in 1833. Between 1836 to 1841, the Kickapoos and Cherokees fought and raided settlers. By 1846, all Indians were removed from the area.

By 1882, cattle and hogs routinely were grazed year-round on native forage in the bottomlands. In 1888, barbed wire was introduced. By 1900, most open range was fenced. Between 1900 and 1944, some bottomland pastures were subjected to high stocking rates of cattle and hogs. Severe overgrazing resulted. In 1950, the intitial purchase of the Derden Wildlife Management Area was made. Cattle and hogs were removed in February 1951 to allow depleted range to recover.

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

During most of this period, the practice of cutting firewood for home heating and cooking had considerable impact on hardwoods (Frentress, personal communication). As rural populations grew, this demand increased and substantial impacts were made on both upland and bottomland hardwood tracts by woodcutters. Within the Catfish Creek ecosystem, local residents have historical records of extensive wood cutting for both rural and urban demands.

During the period from 1950 to 1965, large tracts of hardwood timber throughout the Catfish Creek region were cleared and converted to improved pastures of strains of coastal bermudagrass. However, such activities were excluded from the Engeling Wildlife Management Area.

Today, livestock production continues as the principal land use in the region. Concurrently, farming has declined. Purchase of recreational tracts and rural living in the form of “ranchettes” have become increasing trends since the mid-1970s (Frentress, personal communication).

Vegetation

Originally, bottomlands were open and dominated by large, mature trees. Marshes were covered with blackberry vines {Rubus sp.). Sandflats produced large quantities of postoak grapes {Vitis lincecumii). Green- briars {Smilax sp.) were restricted to a few areas along Catfish Creek. Much of the large timber was cut for rail fences. Mast crops were usually heavy. Farmers and ranchers attempted to prevent fires in the autumn to preserve mast for hogs. However, large, hot fires did occur and usually killed small trees.

In the period 1888 to 1900, barbed wire fences and roads were constructed. Fires were more easily controlled and burning was restricted to early spring. Small trees and underbrush began to appear.

Between 1900 and 1915, wooded portions of the area now known as the Engeling Wildlife Management Area were still parklike. However, underbrush began to increase, but much of the area was open until 1930. Mast crops, usually heavy on mature trees in open areas, began to fail more regularly with the advent of brushy woodland.

By 1950, underbrush was abundant. Bottomlands flooded for long periods, perhaps aided by the loss of upland cover as a result of land clearing and overgrazing. Catfish Creek widened and extensive marshes and swamps developed. These areas became dominated by southern wildrice [cutgrass] {Zizaniopsis miliacea), water-elm [planer-tree] (Planera aquatica), and common buttonbush [buttonwillow] {Cephalanthus acci¬ dent alis).

From 1944 to 1946, Catfish Creek bottomlands were flooded for unusually long periods and the soil remained saturated almost year- round. Subsequently, many large trees died throughout the bottoms. As a

CATFISH CREEK ECOSYSTEM, TEXAS

17

result, the canopy was opened and sunlight reached the ground, which stimulated an immediate impenetrable growth of underbrush and vines.

Logging operations ceased in the Derden Ranch bottomland when it was purchased by the state. Previously, much accessible timber had been removed. Important commercial species included southern red oak {Quercus falcata), willow oak (Q. phellos), water oak (Q. nigra), overcup oak {Q. lyrata), American elm {Ulmus americana), cedar elm {U. crassifolia), sweetgum {Liquidambar styraciflua), and blackgum [black tupelo] {Nyssa sylvatica).

In mid-February 1951, an ice storm damaged stands of several species of bottomland trees: southern red oak, willow oak, water oak, young sweetgum, and river birch (Betula nigra). With the exception of exclusion of logging from the Engeling Wildlife Management Area, large tracts of bottomland timber were cleared throughout the region of Catfish Creek and converted to improved pastures.

On 9 May, 1981, a tornado devastated 71 hectares of bottomland timber in the northern section of the Engeling Area. Fallen timber formed numerous, impassable log jams. The area immediately began to be covered by vines and underbrush.

Wildlife

Prior to 1860, game was plentiful in Catfish Creek bottomlands although the abundance of some species was seasonal. Principal resident game species were white-tailed deer, wild turkey, and gray and fox squirrels. Several species of small mammals were also desirable for eating — North American opossum (Didelphis virginiana), beaver {Castor canadensis), swamp rabbit, and raccoon {Procyon lotor). Other furbear- ers of importance were river otter {Lutra canadensis) and mink {Mustela vison). Important predators were gray fox {Urocyon cinereoargenteus), coyote {Canis latrans), red wolf (C. rufus), and bobcat {Felis rufus). Thousands of waterfowl were present in spring, autumn, and winter, especially when bottomlands were flooded. Passenger pigeons {Ectopistes migratorius) were present in large numbers in winter roosts. Occasionally, the area was frequented by black bears {Ursus americana), mountain lions {Felis concolor), and ringtails {Bassariscus astutus) (Frentress, personal communication).

With the increase of settlers in the region about 1860, bottomland game species began a rapid decline. Hunting occurred year-round with no bag limits. Roost shooting of waterfowl and turkeys was common practice. Commercial game hunters were common Passenger pigeons were exterminated by 1900. Turkeys and deer were depleted by 1920 and with the exception of squirrels and waterfowl, hunting was unproductive. Game laws were passed between 1879 and 1920.

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

After 1920, the principal bottomland game animals were squirrels and waterfowl. Squirrels were abundant year-round and thousands of waterfowl were present in the winter. Demands were high for furbearers, especially for raccoon and mink (Frentress, personal communication).

During years of abundant rainfall and mast production, squirrel and waterfowl populations continued to provide good hunting in suitable habitats. However, after World War II, squirrels and several species of waterfowl were less abundant than in previous years. In 1948, the deer population began a steady increase. The hunting season was reopened in 1955. The herd continues to increase and has spread into adjoining areas. Deer hunting provides major recreation for the locale. Unlike deer, turkeys exhibited a trend of short-term increases for a few years, followed by a steady decline, then an increase. At present, a small huntable population exists in the region.

A summer scent station study of furbearers and predators on the Engeling Area (Stapper, 1984) showed that the raccoon was the most abundant furbearer. Other furbearers were much less abundant. The coyote is the most abundant predator. Quite unexpectedly, tracks of a mountain lion {Felis concolor) were found on 9 June, 1984. Also, nearby scratch marks were observed on large oak trees. Apparently, mink in the Catfish Creek area have recovered from heavy trapping pressure during years of high fur prices and demand.

Current Status and Future Trends

The Trinity River Valley has larger cities, more population, and greater industrial development than any other river basin in Texas (Texas Almanac, 1986-1987). Pollution has been chronic. The upper and middle basins are subjected to periodic depletion of dissolved oxygen due to treated and sometimes untreated sewage effluent-dominated, nutrient-rich waters.

In the Trinity Basin above Catfish Creek, there are 23 existing reservoirs, three projects under construction, and one authorized project. Two of these reservoirs are within 24 kilometers of the Catfish Creek basin (Richland-Chambers and and Cedar Creek reservoirs). The authorized project (Tennessee Colony Reservoir) would inundate the lower reach of the creek.

No portion of the upper Trinity River has or will have a greater amount of reservoir area than the immediate vicinity of Catfish Creek (Texas Department of Water Resources, 1984). More importantly. Catfish Creek is the only tributary of comparable size that has not been influenced by a major reservoir (Leifeste and Hughes, 1967).

The Catfish Creek Basin is situated within the post oak-blackjack oak- black hickory belt {Quercus stellaia, Q. marilandica, and Cary a texana). This belt is a transition zone between eastern Texas pine and hardwood

CATFISH CREEK ECOSYSTEM, TEXAS

19

timberlands and the western blackland prairies. However, the bottom¬ lands are quite diverse and unlike the upland forests and prairies in the vicinity.

Most riparian associations occur along Catfish Creek, but some also are found along large spring-fed branches. Riparian forests occur in about 11 percent of the Catfish Creek Basin. This association has more woody species, larger trees, and more individuals per hectare than any other vegetation type. Thus, it is the most heterogeneous association. About 96 percent of the forest floor is free of herbaceous vegetation.

Many physical and biotic factors influence characteristics of the riparian forest. Major factors are spring and winter floods, shallow topsoils, wind-throw, and a closed canopy. Floods prevent the invasion of plants that are intolerant of water-logged soils. Shallow topsoils over impervious clay subsoils prevent deep-rooted plants as well as tight (low shrink-swell) soils that do not aerate well. Wind-throw topples trees that over-top their neighbors or grow at even slightly vertical angles. The closed canopy prevents sunlight from reaching the forest floor; thus, excluding shade-intolerant plants.

Marshes of the Catfish Creek Basin are dominated by sedges, rushes, bulrushes, smartweeds, burreeds, water-tolerant grasses, and floating¬ leaved plants. They occur in low areas largely devoid of water-tolerant shrubs and trees, but are subject to their invasion. Marshes occupy about four percent of the Catfish Creek Basin (72 hectares). Swamps are dominated by common buttonbush and water-elm. Like marshes, they cover about four percent of the Catfish Creek Basin.

Although marshes and swamps occupy only about eight percent of the Catfish Creek Basin, they are disproportionately important to fish and wildlife. Many species are dependent upon these areas during all or at least part of their live cycle. Also, marshes and swamps are generally more productive in terms of biomass than the surrounding area. Furthermore, many species cannot survive elsewhere.

Physical and biotic factors that caused and maintain these wetlands are flooding for long periods, perhaps aided by the loss of upland cover from land conversion and overgrazing, logging operations, man-caused and weather-caused log jams, and beaver dams.

Most Texas peat bogs occur in a strip from about 80 kilometers east of San Antonio northeast to Louisiana. They are rare, unique, wetland sites. Many of these bogs have been destroyed, primarily by drainage, protection from fire, land conversion, and grazing. If present trends continue, few of these unusual wetlands will survive into the next century.

It is quite significant that three bog sites occur on the Engeling Wildlife Management Area. Although covering only about 2.5 percent of the area (110 hectares), they are important, unusual ecosystems. The largest is

20

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Andrew’s Bog (104 hectares) which surrounds, and is drained by, D. D. Spring Branch. The other two sites are similar to Andrew’s Bog but much smaller. They occur along Gibson and Long branches. Both are springTed.

Two plant communities characterize Andrew’s Bog. A bog-forest community is dominated by red maple (Acer rubrum), ferns, sweetgum, southern wax-myrtle (Myrica cerifera), possumhaw viburnum (Viburnum nudum), and downy vibrunum (V. rufidulum). A treeless community is dominated by several grasses, sedges and rushes — panic grasses (Panicum sp.), spikerushes (Eleocharis sp.), lurid sedge (Carex lurida), and common rush (Juncus effusus).

Around the bog margins are wetland grasses and the bog itself is covered with southern wildrice. Typical bog-specific plants are: sphagnum moss (Sphagnum magellanicum), yellow trumpet pitcherplant (Sarracenia alata), sundews (Drosera sp.), bogmoss (Mayaca aubletii), pipeworts (Eriocaulon sp.), orchids (Pogonia, Calopogon, and Spiranthes sp.), bottle gentian (Gentiana saponaria), Maryland milkwort (Polygala mariana), and yelloweye-grass (Xyris sp.).

Between 1950 and 1965, no grazing was allowed at Andrew’s Bog. However, beginning in 1965, one domestic animal was allowed for every 20 to 24 hectares. Grazing continued until 1977. Vegetation in the bog was burned in winter to increase production. No burning occurred during the winters of 1971-1972 or 1972-1973. Winter burning was resumed in 1980 and 1985 for the purpose of preventing the bog from being overgrown by invading woody species.

Most branches of Catfish Creek are spring-fed. The Engeling Wildlife Management Area has eight significant spring-fed streams. Gibson, Lock, D. D. Spring, Kidd Spring, Long, Berry, Crawford, and Skeet branches. Gibson and Long branches, as mentioned above, have small bog sites. The Gibson Branch, notably, has large stands of hazel alder (Alnus serrulea) along the banks. Immediately below D. D. Spring is a large stand of cinnamonfern (Osmunda cinnamonea) and royalfern (O. regalis), and a stand of possumhaw viburnum. Soils in the bog sites of Gibson and Long branches and below D. D. and Kidd Springs are black, slimy, soft, deep, and quaking. They will not support the weight of a human in many places. The areas below the two springs may be developing bog sites. Kidd Spring emerges from the base of a steep sand bank about 4.6 meters high. It provides constantly flowing, fresh, potable water and is one of the major springs in eastern Texas (Mr. George H. Veteto, retired manager, Engeling Wildlife Management Area, personal communication).

The Catfish Creek ecosystem is (or may be) permanent or temporary habitat for five species that are classified as either threatened or endangered by the United States Department of the Interior and four species that are classified as either threatened or endangered by the Texas

CATFISH CREEK ECOSYSTEM, TEXAS

21

Parks and Wildlife Department. There are no plant species in the area that are listed as threatened or endangered.

The species classified as threatened by the United States Department of the Interior is the American alligator {Alligator mississippiensis). Those species classified by the USDI as endangered are: Houston toad {Bufo houstonensis), wood stork {Mycteria americana), bald eagle (Haliaeetus leucocephalus), and peregrine falcon {Falco peregrinus). Species classified as threatened by the Texas Parks and Wildlife Department are Texas horned lizard {Phrynosoma cornutum) and white-faced ibis {Plegadis chihi), and those classified as endangered by the Department are paddlefish {Polyodon spathula) and Louisiana pine snake {Pituophis melanoleucus ruthveni).

The presence of six of these threatened and endangered species has been verified — American alligator, Texas horned lizard, wood stork, white-faced ibis, bald eagle, and peregrine falcon. A large population of alligators, ranging in size to 4.3 meters, inhabit marshes and swamps. In mid-to late summer, wood storks are attracted to the area to feed in shallow drying marshes and swamps. Recently, white-faced ibis have nested in this region of the state (Telfair, 1980).

Management Needs and Recommendations

Fortunately, about half of the Catfish Creek ecosystem occurs within, or borders the eastern boundary of, the state-owned Engeling Wildlife Management Area (WMA), which is protected and carefully managed. Flora and fauna have been inventorized on the WMA, but few inventories have been conducted above or below it. Such inventories are important, especially in the area of confluence with the Trinity River. This lower reach of Catfish Creek occurs on the Coffield State Prison Farm.

The remaining wetlands of Catfish Creek should be protected from future damage. Several activities threaten the ecosystem and some are operative in the vicinity: 1) strip-mining for lignite deposits; 2) large-scale farming and ranching operations; 3) overgrazing; 4) conversion of large areas to improved pastures; 5) reservoir development; 6) subdivision of large ownerships into smaller tracts; and 7) increase in petroleum production.

Designation of Catfish Creek as a National Natural Landmark officially recognizes this riparian wetland as a significant representative area of the western Gulf Coastal Plain natural region. Such designation does not affect landownership. However, recognition encourages land¬ mark owners to preserve the values of the area. Landowners who agree to protect their property participate in a voluntary nonbinding registration agreement. Their commitment is formalized by the National Park Service. Each landowner is eligible to receive a certificate that

22

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

identifies the special status of the area. In addition, a bronze plaque may also be presented for appropriate display on the site.

Although further study could contribute more data, thorough studies have been made in about half of the Catfish Creek ecosystem. These studies document that these bottomlands are of such significance that they are worthy of inclusion on the Registry of Natural Landmarks.

Acknowledgments

I am grateful for the cooperation and information of personnel of the Gus A. Engeling Wildlife Management Area: Mr. George H. Veteto, Manager (retired); Mr. Harry H. Haucke, Manager; Ms. Julie A. Hogan, Wildlife Biologist; and Mr. Kenneth E. Karlsen, Wildlife Technician. I especially wish to thank the following persons: Mr. Carl D. Frentress, Assistant Waterfowl Program Leader, North Central and Piney Woods Regions, Texas Parks and Wildlife Department, for his numerous suggestions, valuable information, and editorial expertise; Ms. Mary E. May, School of Forestry, Stephen F. Austin State University, for sharing her lists of plants and herbarium specimens; Dr. David D. Diamond, Plant Community Specialist, Texas Natural Heritage Program, for his helpful editorial comments, suggestions, and encouragement; and Dr. Frederick R. Gehlbach, Department of Biology, Baylor University, for his review of the manuscript and vertebrate checklists and his helpful editorial suggestions.

Literature Cited

Davis, C. E., and G. H. Veteto. 1978. A history of the Gus A. Engeling Wildlife Management Area. Texas Parks and Wildlife Dept., Pittman-Robertson Proj., Texas W- 54-D and W-74-R, PWD Brochure 7000-10.

Engeling, G. A. 1951. History of the Derden Wildlife Management Area. Job Completion Rept. 52-R-l, Job I, Texas Game and Fish Commission, 15 November 1950-30 June, 1951, 13 pp.

Leifeste, D. K., and L. S. Hughes. 1967. Reconnaissance of the chemical quality of surface waters of the Trinity River Basin, Texas. Rept. Texas Water Development Board, 67:1-65.

Lodwick, L. N. 1975. Net aerial primary production of three East Texas peat bogs. Unpublished M.S. thesis, Baylor Univ., Waco, Texas, 87 pp.

Stapper, R. J. 1984. A survey of furbearing species and their habitat preferences on the Gus A. Engeling Wildlife Management Area. Unpublished research project, Texas A&M Univ., College Station, 12 pp.

Teer, J. G. 1952a. Vegetation of the Derden Wildlife Management Area. Job Completion Rept. W-52-R, Job IV, Texas Game and Fish Commission, 16 November, 1950-15 November, 1951, 35 pp.

- . 1952b. Wildlife of the Derden Wildlife Management Area. Job Completion Rept.

W-52-R, Job V, Texas Game and Fish Commission, 16 November, 1950-15 November, 1951, 21 pp.

Telfair, R. C. H, and K. A. Arnold. 1974. A tentative checklist of the birds of the Gus A. Engeling Wildlife Management Area and Anderson County, Texas. Texas Parks and Wildlife Dept., Pittman-Robertson Proj., Texas W-54-D and W-74-R.

Telfair, R. C. H, and C. O. Martin. 1974. A tentative checklist of the mammals of the Gus A. Engeling Wildlife Management Area and Anderson County, Texas. Texas Parks and Wildlife Dept., Pittman-Robertson Proj.: Texas W-54-D and W-74-R.

Telfair, R. C. H, and R. A. Thomas. 1974. A tentative checklist of the amphibians and reptiles of the Gus A. Engeling Wildlife Management Area and Anderson County,

CATFISH CREEK ECOSYSTEM, TEXAS

23

Texas. Texas Parks and Wildlife Dept., Pittman-Robertson Proj., Texas W-54-D and W- 74-R.

Telfair, R. C. II. 1977. A tentative checklist of the freshwater fishes of the Engeling Wildlife Management Area. Texas Parks and Wildlife Dept. PWD Brochure 7000-8.

- . 1980. Additional inland nesting records in Texas of four species of colonial

waterbirds. Bull. Texas Ornithol. Soc. 13:11-13.

Telfair, R. C. II, N. J. Baumgartner, K. B. Edmondson, S. H. Garner, C. M. Martin, P. D. McKone, L. A. Neely, J. M, Petrofes Lubbering, D. L. Rakestraw, R. J. Stapper, P. E. Topke, and T. A. Wright. 1984. Survey of wind-thrown trees, den trees, and snags, Gus A. Engeling Wildlife Management Area. Unpublished research project, Texas A&M Univ., College Station.

Texas Almanac. 1986-1987. A. H. Belco Corp., Dallas, 768 pp.

Texas Department of Water Resources. 1984. Water for Texas: a comprehensive plan for the future. Austin, 1:1-72.

Veteto, G. H., C. E. Davis, R. V. Hart, and L. N. Lodwick. 1976. A tentative checklist of the vegetation of the Gus A. Engeling Wildlife Management Area and Anderson County, Texas. Texas Parks and Wildlife Dept., Pittman-Robertson Proj., Texas W-54- D and W-74-R.

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JIM WELLS COUNTY UNIT ROAD SYSTEM:

A CONTINUING SAGA OF SOUTH TEXAS POLITICS

Ross N. Dudney, Jr.

Department of History, Texas A&I University, Kingsville, Texas 78363

Abstract. — This is an in depth field study of the Unit Road System, which is receiving renewed interest in some counties in Texas due to the need to conserve tax dollars in a declining economy. This study followed the attempt to adopt, on a local-option basis, such a system in Jim Wells County, Texas. The results show that the question of South Texas politics, with deep-seated political concerns such as elitism and status quo biases, may stand in the way of what would appear to be the path of common sense. Key words: elitism; ethnic biases; partisan politics; political patronage.

In 1985, Jim Wells County, Texas, authorities were forced to provide an election to decide if the county taxpayers desired to place the county road system under the management system termed the Unit Road System. Given the indisputable face value of better cost accounting, control, and more efficient methods of the Unit Road System, along with the severe economic conditions existing at the time, it appeared that the choice of beleaguered taxpayers would be affirmative.

Such was not the case. To me, both an observer and a limited participant, this became a hands-on lesson about South Texas politics, complete with many of the elements that gained national exposure during the 1940s and 1950s when the political reputations of Duval County and Jim Wells County reached their zenith. Faded memories of the infamous “Box Thirteen” controversy involved in the Coke Stevenson-Lyndon Johnson campaign returned, along with remembered stories about county politics in South Texas communities. Political Science textbook theories became animated as this political campaign unfolded. Case histories exposing past instances of county politics as usual, fiefdoms ruled over by individually elected county commissioners, decentralized, patronage- ridden, rural-oriented, mismanaged (bordering on the corrupt), and informal, “good ol’ boy” politics took on new life. There was no violence or radical expose, but such things as the biases of politics as usual and of the reform groups became more meaningful when observed in action. For the most part, the classroom theories can be identified in such a field exercise. However, it is most interesting to observe how political theory or structure, as well as public law, can be circumscribed or prostituted by real politics. South Texas style.

One of the most significant functions of county government in Texas is the responsibility for the rural roads within its jurisdiction. The management of these roads involves huge outlays of tax dollars. Certainly no one would argue against the importance of well-maintained

The Texas Journal of Science, Vol. 40, No. 1, February 1988

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

highways in the era of the automobile and in a state so large as Texas. Indeed, the highways are one of the unifying, civilizing factors in this or any other age (Gilbertson, 1917). They are commercially necessary in order that produce may reach markets, goods come to the hands of consumers, and students attend schools no longer located in remote, rural villages, but in consolidated systems of larger communities. The absolute necessity of adequate roads and the high cost of construction and maintenance of roads make it imperative that counties operate their network of roads in the most efficient and economical way possible.

There exist in Texas two broad systems by which county governments set policy, make decisions, and implement the operation of their roads. The older of the two systems generally is termed the precinct system. In its pure form, a county’s road funds are divided, by commissioner court agreement, largely arbitrarily and often as result of negotiation, among the commissioners (Givens, 1983b). Each county commissioner operates a separate facility, located in his own precinct, for storage of supplies and maintenance of equipment. The commissioner employs and terminates his own road personnel, orders and purchases supplies, handles complaints and requests, and decides which road work will be done, and when and how the work will be done (Call, 1959). In essence, the commissioner becomes the road administrator of his precinct with absolute authority in his “own personal road fief” (Givens, 1983a). One major and repeated complaint about the precinct system is that county roads are administered by elected officials, who often are totally unqualified for this particular part of their job. This is not a new complaint, as this passage, originally written in 1917, reflects:

The whole public road function is rooted, historically, in the tradition of the people’s infinite political versatility and infallibility. The true democrat of the nineteenth century never doubted his ability to select and control the human agents for executing a technical and difficult engineering problem, which has baffled the resources of modern specialists. And so, to this day, the management of road construction and care over a great portion of the country is entrusted to a farmer, a blacksmith, a plumber, or some other species of layman who has sufficient popularity with his neighbors and the county chairman to get himself chosen as county supervisor (Gilbertson, 1917).

The newer system by which Texas counties can operate their roads generally is termed the County Unit Road System. In 1947, the Texas legislature passed an act labeled as the Optional County Road Law under which county commissioners can establish a county road department under the direction of a county road engineer, who would supervise all road work in the county and supervise all county road-crew employees (Carrico, 1984). This system of road administration is used in whole or in part in a majority of the states (Corpus Christi Caller-Times, 28 July 1984). In Texas, it exists on a local-option basis (Call, 1959), and a county can adopt the unit road system by a majority vote in a special election called for by petitions containing signatures numbering 10

JIM WELLS COUNTY UNIT ROAD SYSTEM

27

percent of the county vote for governor in the last general election (Call, 1959).

Proponents of the County Unit System point to an impressive array of improvements possible under the centralized reorganization that results from the new system. An important improvement lies in the area of accounting and budget control. The unit system, if directed by an able administrator, can encompass up-to-the minute budget control, keeping expenditures in line with anticipated revenues. Further, centralized management and financial reporting is useful to commissioners in making policy and budget decisions. In precinct systems, trying to get a firm grasp of county expenses is “like trying to squeeze ice cream. There are too many expenditures from too many accounts kept in too many books, if kept at all” (Givens, 1983a).

An additional savings under the Unit Road System results from the cessation of duplication, yea even quadruplicating, of road machinery. And the road equipment can be maintained better in a central shop where systematic pooling allows for maximum usage. Information from officials of counties that recently adopted the Unit Road System confirms this. The auditor of Tom Green County, of which the city of San Angelo is the county seat, reported that his county saved $225,000 the first year of its centralized operations because it was able to eliminate the need for heavy equipment that commissioners had planned to purchase (Givens, 1983a). Walter Neaves, the county engineer in Bell County of central Texas, reported that in the two years since adoption of the Unit Road System, the county had reduced the number of pieces of equipment by about 25 percent (Givens, 1983c). Heavy construction equipment required for road maintenance certainly represents a large investment of taxpayer dollars and judicious reductions in this necessary element of road work should be welcome. Also, a centralized professional road administration minimizes favoritism, waste, and abuses, such as work performed by county equipment and county employees for private interests. Taxpayers also get more for their money when county commissioners are freed from daily road operations and the politics of roadbuilding, giving them more time to spend in county administrative, financial, and policy matters (Givens, 1983c). The strongest argument for this system lies in the fact that it is less expensive to operate a Unit Road System than a precinct system. Exhaustive studies of counties that have had the unit system for more that 30 years show, conclusively, that this system is more efficient and less expensive than the precinct system (Givens, 1983c).

Given this evidence, the question continues to plague: Why have only 39 counties in Texas taken advantage of this opportunity to insure the most judicious use of tax dollars? Why is Texas the only state that continues to use the archaic, precinct method to administer the majority of its county road systems? Perhaps an examination of more recent

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

county excursions into these areas will shed some light on these questions.

In 1984, the voters in Nueces and Bee counties approved Unit Road Systems. However, the margins of victory were narrow, and proponents of the system had been trying to win its adoption since 1948. It is interesting to note that Nueces County records of road fund expenditures reveal total expenditures of $2,786,195 for the period of 1 January 1984 through 30 June 1984 and total expenditures of $2,150,177 for the same period of time in 1985 after the Unit Road System was instituted (unpublished data from Bob Barnes, County Judge, Nueces County, Corpus Christi, Texas).

On 5 November 1985, Jim Wells County voters turned down a Unit Road System by a vote of 2409 to 1515. Approximately 18 percent (3924) of the registered voters of Jim Wells County decided this issue for the approximately 45,000 people who live in the county (Alice Echo-News, 6 November 1985). At the time of the vote, the citizens of this county were facing a 13 percent tax increase and the knowledge that the county owed the taxpayers a refund of approximately $400,000 that it could not pay. Questions regarding these complex matters cannot be answered by the simple statement that the voters have had their say.

Because I am a resident of Jim Wells County and had previously completed a research project on the Nueces County Unit Road System, I was asked to present findings from the research project to an elite group named the Jim Wells Master Planning Association. This group is a classic example of an economically-based, traditional Anglo establish¬ ment. The presentation was given to this group on 25 March 1985. Two of the county commissioners and the county judge were in attendance although they are not members of the group (unpublished minutes, Jim Wells County Master Planning Association, 25 March 1985). On 18 July 1985, I was asked to assume the position of researcher on the publicity committee of the Jim Wells Master Planning Association as this group moved toward a plan of action to promote a County Unit Roat System (unpublished minutes, Jim Wells County Master Planning Association, 22 July 1985). In the ensuing months, I observed political bias, elitism, status quo orientation, and ethnic group considerations in a new light, not the light of classroom theory, but that of actual everyday practice.

The Jim Wells Master Planning Association is made up of economic leaders of the community. While a few members are Mexican-American, the vast majority are Anglo, and all officers are Anglo. The majority of Jim Wells County officials are Mexican-American and the majority of the registered voters are also. So the conflict was one of an economically- based, traditional, Anglo establishment, seeking to alter the status quo, confronted by a recalcitrant and more popularly based minority ethic elite, whose power rests on numbers, organization, and public office.

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One revelation concerned the Right to Information Law. It does exist, but all governmental offices like to function in private and many “smoke screens” can be raised before the legitimate request of a citizen for information will be honored. It took almost two months to secure copies of the Jim Wells County budgets from 1983 up to 1985, and copies were secured only after a request forwarded by an attorney. It took almost two weeks to get the county surveyor to release the number of miles of county roads in Jim Wells County. He felt he had to have permission from the county auditor before he could release this “important” information.

When the information was received (only three years of five years requested were received), it was learned that this county had no cost accounting procedures and that county budgets were estimates only and made up, in final form, at the end of the year. In this case, final budgets showed what occurred and were not used during the year as a method of controlling county spending. One revelation provided by these “budgets” was that the cost of maintaining 557 miles of county roads has increased each year (Jim Wells County Budget, 1983-1985 pp. 46-62). No new county roads have been built in Jim Wells County since 1948. Also, there was no inventory of county equipment. All expenditures were for maintenance. A visit to the County Court during regular session also was of interest. Each commissioner presented his weekly bills in the form of a large brown envelope presumably stuffed with supportive invoices. These envelopes were not opened and examined, but the total amount was routinely approved upon a voice vote when the commissioner presenting the brown envelope stated: “I have billings for $10,000 [or whatever amount] this week.” Examination of the contents of some of the brown envelopes revealed some actual business invoices. However, many of the “invoices” consisted of white pieces of paper (chits) with such notations as: “I owe Joe’s back-hoe service $50.” It was observed that the number of these “chits” increased as the dates of elections grew nearer.

The single highest expenditure in the county budget was for labor. The political patronage system of hiring by individual commissioners was one of the strongest reasons given by commissioners for not supporting the Unit Road System. One commissioner told me that he felt it was important to be able to hire someone who “needs to work a couple of weeks to pay his electric bill.” Note that the criteria for hiring this “worker” are not that the county is short-handed or that the “worker” is especially qualified for some position, but that he needs to work for two weeks to pay his electric bill. It would seem illogical to attempt to refute the assumption that such hiring practices pay special dividends when commissioners face reelection.

Elitism is also present in the ranks of those who attempted to reform the Jim Wells County road system. This movement was headed by a local

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banker who was president of the local branch of a large banking group. He was assisted by a local businessman, one of the largest employers in the county. The local banker held many “committee” meetings in is offices in order to “see where we are.” On one occasion (16 October 1985), he called 36 men on the telephone and informed each of them, “I need a check from you for $250 to help pay for our advertising program for the Unit Road System. Have your secretary run it by my office tomorrow.” He also contracted with Morehead, Dott, and LaPorte, Inc., to provide surveys and phone banks, advertising, and consultations for which they presented a billing estimate of $15,150 (unpublished billing, Morehead, Dott, & LaPorte, Inc., 1985). It is interesting to note that the men called did not turn the local banker down. As a matter of fact, this writer was approached by him for a contribution and dutifully wrote out his check for $200.

On another occasion, (17 October 1985), the local banker called the businessman who was assisting and asked him if he would supply 10 to 20 of his “girls” to serve as telephone survey operators each night from 5:30 PM until 8:30 PM for seven nights. The businessman stated he would and the matter was settled. The “girls” were employees of the businessman’s company, and one wonders if they were asked if they were for this new system or if they were simply told they needed to help with this matter. At any rate, they did show up and called more than 3000 voters to urge them to vote in this election. They were supplied with a fact sheet giving information on the Unit Road System designed to influence voters to vote for this system. An interesting side note is that on 29 October 1985, a commissioner entered the local banker’s building at about 8:00 PM and began to harass the girls who were working the telephone survey. The local banker was called, and, upon his arrival, he entered into a heated argument with the commissioner and ordered the commissioner out of the bank.

The commissioners and county judge did not openly oppose the Master Planners during the petition drive, but when the petitions were presented to the county clerk on 30 September 1985, the county judge, Roberto Guerra, made his presence felt at once. He first ordered the county clerk to verify the signatures of each petitioner by comparing the signature on the petition with the signature on the petitioner’s voter registration card. The county clerk reminded the judge that this would not be possible because it is legal for husbands and wives to sign each other’s voter registration card. The Master Planners held an emergency meeting on Tuesday, 1 October 1985. At this meeting, attorney Homer Dean told the group, “Judge Guerra does not plan to put the petition on the agenda.” Mr. Dean also told the group, “Guerra doesn’t have the authority to keep it off the agenda.” The Master Planners voted to seek a writ of mandamus in district court if the item was not placed on the agenda. If

JIM WELLS COUNTY UNIT ROAD SYSTEM

31

successful, such action would force the judge and court to “perform its duty” (unpublished minutes, Jim Wells Master Planning Association, 1 October 1985). The following day, I was instructed by the banker to go to the offices of one of the community’s leading citizens, Mr. Lucien Flournoy, to inquire what pressures might be exerted on the judge or court to force compliance with the wishes of the Masters Planners. Mr. Flournoy, a successful oil man, is a staunch Democrat and is an intimate friend of many Democratic political leaders in both Austin and Washington, D.C. A vice president of Mr. Flournoy’s company, Mr. Peterson, made one short telephone call to Austin. In about five mintues, a member of the staff of the office of the secretary of state called and informed us of sections in the state statutes whereby the Master Planners could bypass the county judge and force this matter on the agenda by only two commissioners calling for the election. At this point, two commissioners were willing to do this. By Friday, 3 October 1985, the judge “threw in the towel,” and the county court voted unanimously to place this matter on the November fifth ballot. The Jim Wells Master Planning Association breathed a sigh of relief and made plans to build a speaking group to “educate the public.”

Three days before the election, the commissioners passed a resolution against adoption of the Unit Road System. Commissioner Laughlin stated: “We think the people who are for the Unit Road System are sincere but we think they are wrong. Members of the commissioners court are most knowledgeable about road and bridge matters. This is the best system of all. The only way to really serve the people of this county is with the present system” (Alice Echo-News, 3 November 1985). Each of the commissioners bought large blocks of time on all the local radio stations and provided negative messages, in both English and Spanish, regarding the Unit Road System. Their major thrust was that this new system would cost many workers their jobs, decrease services to rural areas, and increase cost because of a large central staff. On election day, commissioners provided drivers and buses to bring voters to the polls.

Given the evidence supporting the Unit Road System, it appears that common sense should assert itself in the realm of county government. The Unit Road System brings coherence and efficiency to county roadbuilding and maintenance operations: it eliminates duplication and waste. The idea is clearly a winning one (Editorial, Corpus Christ! Caller- Times, 17 October 1985). However, partisan politics, elitism, biases, and ethnic questions may stand in the way of common sense. In this case, it appears that the voters have spoken, but not necessarily to the issue at hand. Precincts Three and Four represent the communities of Orange Grove and Premont, which are located in the northern and southern most parts of the county, respectively. The vote indicates these communities feared loss of jobs and services if the Unit Road System was

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passed and then centralized in the county seat of Alice. Their commissioners had told voters this centralization would likely occur. To these outlying communities, such information, though false, caused them to view the Unit Road System as an anathema. In Alice, the vote appears to have been heavily influenced along ethnic lines. The speakers for the Master Planners were mostly Anglos and either attorneys or successful businessmen. These speakers spoke to such groups as the County Bar Association, Alice Realtors, and The Desk and Derrick Club. The rural and Mexican-American voters undoubtedly perceived this group as Anglo elitist, both politically and economically. The Master Planners attempted to work their message from the top down. The opposition did just the opposite. The results are now history.

Given the economic conditions of shrinking tax revenues and growing expectations for services, it would appear that this question will have to be considered again in the near future. Perhaps experiences of some sister counties that have just changed over to the new system will provide enough hard evidence to enable those in Jim Wells County to put aside partisan and ethnic feelings in the interest of providing the best possible use of hard-earned tax dollars to give every citizen the best quality of life possible.

Literature Cited

Call, T. 1959. The county-unit road plan. Caller-Times, Corpus Christi, Texas, 15 November.

Carrico, L. 1984. Judge touts unit-road system idea. Caller-Times, Corpus Christi, Texas, 28 July.

Gibertson, H. S. 1917. The country. The Kinckerbocker Press, New York, 95 pp.

Givens, M. 1983a. Unit road system can save taxpayers money. Caller-Times, Corpus Christi, Texas, 1 1 September.

- . 1983b. Unit system: Nueces County spends more than Bexar to keep up fewer

road miles. Times, Corpus Christi, Texas, 12 September.

- . 1983c. Road budget: it costs Nueces County more to maintain roads than unit

counties. Caller-Times, Corpus Christi, Texas, 13 September.

THE COUNTY UNIT ROAD SYSTEM: ANOTHER VIEW

J. D. Phaup

Department of Political Science, Texas A & I University,

Kingsville, Texas 78363

Abstract. — Ross Dudney’s article on the defeat of the County Unit Road System in Jim Wells County offers a useful account by an “insider” of county-level politics in South Texas. Dudney seems inclined to accept the reformers’ rationalization that their actions were in the name of economy and the public interest. Opponents are seen as acting irrationally, selfishly, or both. An alternative explanation is that everyone involved acted consistently with his self-interest. Reformers appear to have been members of a local economic elite advancing its own interest. Opposition leaders form a subordinate, partially co-opted, political elite seeking to protect its power base. The strongest voter opposition came from rural and minority voters who evidently feared loss of employment opportunities or governmental services geared especially to meet their needs, or both. Citizens with no special interest in preserving the existing system were more likely to vote favorably on the proposal, which promised to make more economical use of their tax dollars. Key words: County Unit Road System; local government; reform model; politics-management dichotomy; Texas.

South Texas politics is the subject of an abundance of myth, rumor, secondhand reports, often self-serving personal papers and memoirs, and of many “tall tales.” Lacking, however, is a substantial body of reliable, carefully researched, professionally competent studies of politics in the region. There are a few notable exceptions (Shockley, 1974; Anders, 1982) to this exclusion. Dudney’s study (previous article in this volume) of Unit Road System politics in Jim Wells County now may be added to the list of exceptions. Dudney offers a rare, carefully researched glimpse into the inner workings of an established Anglo elite in a predominantly Mexican-American South Texas community. Taking good advantage of his position as a participant-observer, Dudney remains faithful to his scholarly responsibility to report, as fact, only that which he was able to observe directly, or to verify through reliable sources.

This essay neither challenges the facts offered by Dudney, for they seem unassailable, nor does it seek to glorify politics as usual in Jim Wells County. However, any body of factual information about politics is open to multiple interpretations. Dudney views Unit Road System politics from a particular perspective. His perspective is that of the reform model of local government. My position is that this model, while applicable to the reform effort studied by Dudney, provides, at best, an incomplete explanation of what the reformers sought to accomplish. The alternative view offered here is based on several published critiques of the reform model (Merton, 1957; Hays, 1964; Lowi, 1967; Harrigan, 1981; Jones, 1983; Judd, 1984). Both perspectives are heavily normative, biased.

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and incomplete. Taken together, however, they should help to clarify the nature of the issues raised by the proposed Unit Road System, and some of the likely consequences should the system win adoption.

There is no significant political science literature on the Unit Road System itself or on its political implications. This is another gap that Dudney’s study will help fill. There is, however, a significant and related literature that focuses on municipal reform (Steward, 1950; Childs, 1952). The Unit Road System is closely modeled on the council-manager form of city government, which is the centerpiece of the set of structural improvements sought by reformers at the municipal level. Inasmuch as both the Unit Road System and Dudney’s own perspective embody the major assumptions of the municipal reform movement, an examination of the reform model may help clarify the objectives and potential consequences of the effort to reform policy-making and administration with respect to county roads in Jim Wells County.

The Reform Model of Local Government

The reform model rests on the normative judgment that politics and power are unnecessary and undesirable in the management of local public affairs. The municipal reform model includes, besides advocacy of the council-manager form, a call for at-large nonpartisan elections, civil service systems, the initiative, the recall, and the referendum. The reform model presumes that a sharp distinction can, and should, be drawn between politics and administration (Harrigan, 1981:92; Jones, 1983:249; Judd, 1984:98). Politics involves power and is necessary where values and goals are unsettled. Fortunately, reformers believe, such is not the case when it comes to running local government. At the local level, the ends of government seem clear-cut and not subject to legitimate dispute. The business of local government is to provide services: streets, utilities, police and fire protection, parks and recreation, and others. These services should be administered as efficiently and economically as possible to provide maximum benefit to all citizens. Local government should be run like a business — that is, according to principles of scientific management. These principles are believed to be subject to objective (scientific) definition and application by professionally-trained experts (career administrators or managers), who should be charged with responsibility for managing local affairs with minimal interference from elected (that is, political) officials. Besides efficient, cost-effective operation, the only major legitimate objective of local government is to encourage economic development (promote a favorable business climate) for the community as a whole. At its best, reformers believe, a reformed local government should “be run not only as a business but for business” (Judd, 1984:113- 114).

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For reform advocates, the choice is a simple one between honest, moral, rational, efficient, low-cost, nonpolitical, local government, dedicated to economic development and the public good, or its opposite. The opposite, unreformed local government, is seen as political, partisan, irrational, inefficient, undemocratic (boss-ruled), catering to parochial and selfish interests, patronage-ridden, prone to favoritism, and often corrupt. (For more information concerning the tenets of reform, consult: Lowi, 1967:99-100; Harrigan, 1981:88-104; Jones, 1983:240-255; Judd, 1984:84-107.)

Critique of the Reform Model

The reform model has shaped much of the structure of local government since the early 1900s (Judd, 1984:90-96). The model still is accepted by many political scientists (Jones, 1983:249) and is the prevailing doctrine among those who train management-level personnel for local governments. The model, however, has been subjected to a piercing critique by political scientists who specialize in urban politics and public policy (Lowi, 1967:83-92; Harrigan, 1981:93, 107-113; Jones, 1983:256-260; Judd, 1984:107-114). This critique, though dismissed by admirers of the reform model, has become firmly ensconced in textbooks on public policy and urban politics (Jones, 1977; Harrigan, 1981; Jones, 1983; Judd, 1984).

Whereas the reform model begins with the assumption that politics and administration must be kept distinct, the critique of reform denies this possibility and assumes the inevitability of conflict in the process of governance — even in its administrative phase. What we have are two vastly different conceptions of government. “One views government as ... an exercise in technology” (Jones, 1983:259). The other sees government “as a way of resolving competing [claims]” (Jones, loc. cit.). For one, “‘politics’ is a dirty word” (Lowi, 1967:86); for the other, it is the essential lubricant that makes social life and governance possible. From the latter point of view, the reform ideology’s denial of politics is either hopelessly utopian or simply a guise masking the reformers’ own political program.

Critics of reform strongly resist the notion that local public interest can be objectively identified. In practice, governmental policies and their implementation always bring “disproportionate benefits to some . . . and disproportionate costs to other[s].” “All actions are biased.” “There is,” quite simply, “no absolutely fair way to apportion the costs and benefits of [public policy]” (Harrigan, 1981:5). What reformers characterize as a contest between politics and impartial administration is, for critics, simply a political conflict over who should rule. The issue, then, is not ''whether'' reformed governments will be politically responsive, but “to whom and under what circumstances" (Jones, 1977:221).

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Administration, or policy implementation, is inherently politicized in reformed structures for two reasons. The first is that, regardless of the level or structure of government, politically responsible policy-makers commonly delegate the resolution of difficult political issues to either appointed or career administrators. The result is sometimes labeled ‘“administrative discretion’”; whatever it is termed, what it amounts to is the power to “‘interpret’” the meaning of policy; and that becomes the power to decide (Jones, 1977:152). Gaus (1947) noted that administration involves not merely management, but “a reconsideration of the policy being implemented.” Lowi (1969:126) maintained that the extent of such delegation of power is often so great that the consequence is “‘policy without law.’”

The second reason that administration is increasingly treated as politicized is that “bureaucrats themselves are involved in other [phases of policy-making]” (Jones, 1977:140). Specifically, administrators often play a key role in the formulation and implementation of the broad policies they are later charged with implementing. This is especially true in reformed local structures. Typically, elected legislators and executives are part-time, citizen-politicians who lack the time, experience, or information to exert either strong policy leadership or effective oversight over a hired manager. In the council-manager form of municipal government, it “is, more often than not, the [city manager] who initiates policy proposals” (Harrigan, 1981:102). It is he to whom citizens and community organizations look for policy leadership. Most often the manager’s recommendations are accepted by the council. If reform advocates were to have their way, things would be much the same in the county with adoption of the Unit Road System accompanied by its professionally-trained county engineer-administrator.

Critics of the reform model agree on two points concerning the political consequences of reformed structures: 1) those structures have an upper-class bias, and 2) reformed structures are not particularly responsive to political demands (Hays, 1964; Lowi, 1967; Jones, 1983; Judd, 1984). “Empirical results uniformly document [the] upper-class [status of reformers]” (Judd, 1984:116). Reformed government does not bestow immediate, obvious, substantive policy benefits on upper-class elements. It does, however, in the name of taking politics out of local government, restructure policy-making so that it is more responsive to upper-class, business interests. This is accomplished by transferring critical decision-making opportunities from elected officials to “Neutral Specialists” (Lowi, 1967:87). These bureaucratic power-wielders are frequently inaccessible to people who lack the advantages of education, status, and wealth. Career administrators are, however, “much easier [for upper-class business leaders] to handle than the politically sensitive, elected commissioners” (Judd, 1984:109). The professional manager needs

COUNTY UNIT ROAD SYSTEM— ANOTHER VIEW

37

the cooperation of business and community leaders to achieve his own objectives, especially that of economic development. Members of elite groups instinctively clothe their appeals for private gain in the respectable reform rhetoric of the public interest. Lower-class and minority citizens may unknowingly breach the local administrator’s sense of ethics and propriety by making unmasked appeals for governmental assistance with private or parochial problems. One critic laments; while traditional politics may have been corrupt, they “were sometimes responsive to working class constituencies. The new [reformed] bureaucracies . . . [are] not likely to be responsive at all” (Judd, 1984:114).

Other consequences of reform indicate that many municipal reform objectives have, indeed, been accomplished. While graft and inefficiency have hardly been eradicated, reformed municipalities are typically more efficient and cost effective than unreformed municipalities. They spend less, tax less, and tend to be more supportive of “public-spirited” projects sponsored by establishment leaders. Theodore Lowi is unimpressed. Such communities, he wrote, are “well-run, but ungoverned” (Lowi, 1967:87).

A caveat seems prudent at this point. It is almost a truism that reforms of political structure never live up entirely to either their stated or unstated objectives. Further, reforms usually have entirely unanticipated, if not wholly undesirable, consequences as well as those that may have been sought. Thus, the actual consequences of municipal reform have often been less far-reaching than would have been anticipated in view either of the reform model or of the critique of that model. In addition, it is doubtful that the proposed Unit Road System incorporates sufficient structural features from the municipal reform package to fully support the expectations of unit road advocates. This caveat to one side, however, the proposed Unit Road System, typical of reform in general, would likely, if implemented as planned, best serve the interests of its own advocates.

The Unit Road System: Politics or Neutral Management

Dudney is not a traditional reform advocate. He is objective enough to recognize the elitist nature of support for the Unit Road System in Jim Wells County. However, he does seem to attribute elite support more to the public-spiritedness of the elite than to its self-interest. In this, and other respects, his study closely adheres to the main tenets of the reform model. The existing precinct system is castigated for a plethora of defects. The system is said to be decentralized, patronage-ridden, rural-oriented, mismanaged, and subject to favoritism and waste. It is characterized as informal “good ol’ boy” politics that borders on corrpution. One commissioner was so unrepentant that, according to Dudney’s report, he claimed the patronage system was an advantage of the precinct system.

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

In contrast, Dudney cites for the Unit Road System all the advantages usually claimed for reformed structures at the municipal level. It is his belief that counties should operate their roads as efficiently and economically as possible. He believes that the Unit Road System is less expensive to operate, and he sees reduced cost as the strongest reason for adopting the system. The system would also reduce favoritism, waste, and other abuses. Consequently, Dudney is convinced that people would receive a better return on their tax dollars. The Unit Road System, like reformed municipal structures, is lauded for its businesslike approach to providing governmental services.

Voter rejection of the Unit Road System poses difficult questions for defenders of the reform model — questions that Dudney contends are not answered by simply saying the electorate has spoken. He is puzzled that voters would reject a system that experience has proven to be more cost- effective than the existing precinct system. Although Dudney laments the electorate’s lack of common sense, his article supplies an adequate, commonsensical explanation of why voters rejected the Unit Road System — that explanation is simple self-interest. As he reveals, the vote was along ethnic and urban-rural lines. Rural and Mexican-American voters evidently saw reform proponents as members of the local Anglo power structure. Their perceptions are confirmed by Dudney’s own observations. He characterizes the lead reform organization, the Master Planning Association, as an element of a local economically-based Anglo elite. The Master Planners, Dudney confirms, sought to exercise influence strictly from the top down. The opposition pursued a bottom-up strategy that, not surprisingly, proved popular with more voters.

Dudney’s explanation of the behavior of Unit Road System opponents is quite satisfactory. However, his attribution of higher motives to reform advocates is, on close examination, less convincing. To critics of reform, there is nothing particularly reprehensible about political actions being guided by self-interest. They do not deny a role for altruism in politics, but tend to feel that self-interest usually provides a better explanation of political behavior than does altruism. In this situation, behavior on both sides of the Unit Road System issue can be explained in terms of the tangible or symbolic self-interest of the participants, or both. Some of the evident interests at stake in the Unit Road System controversy for each of four major categories of participants are reviewed in Table 1.

The review of anticipated consequences of the Unit Road System reveals that elite supporters of the reform proposal, however disinterested and altruistic their motives, felt they had nothing to lose and quite a bit to gain from its adoption. Urban, middle-class residents, especially Anglos, would be marginally better-off, but their gains would mostly be collective (shared equally by all residents) and symbolic in nature (see Dahl, 1984:104-106, for a discussion of “collective goods”). Lower-class,

COUNTY UNIT ROAD SYSTEM— ANOTHER VIEW

39

Table 1. Anticipated effect of Unit Road System on interests of participants.

		Nature of effect
Category of participant	Positive	Negative
1. Angelo establishment
a) Tangible interest	1) Less costly roads 2) Lower taxes 3) Economic development 4) Special advantages for some businesses 5) Better benefits for urban areas	None
b) Symbolic interest	1) More “public regarding” policy	None
2. Anglo, urban voters
a) Tangible interest	1) Less costly roads 2) Lower taxes 3) Better benefits for urban areas 4) “Trickle down” from economic development	None
b) Symbolic interest	1) More “public regarding” policy	None
3. Minority, lower-class
and rural voters a) Tangible interest	1) Less costly	1) Loss of job opportunities
	roads	for a few
	2) Lower taxes	2) Loss of business
	3) “Trickle	opportunities for a few
	down from	3) Loss of opportunities
	economic	for special services
	development
b) Symbolic interest	None	1) More distant and impersonal administration 2) “Our guys are out, their’s are in”
4. Minority, rural-oriented
elite (county commissioners) a) Tangible interest	1) Less costly	1) Loss of control over political
	roads	resources (jobs, contracts, favors)
	2) Lower taxes 3) “Trickle down” from	2) Loss of power and position
	economic
	development
b) Symbolic interest	None	1) Loss of ethnic or rural community pride and sense of importance (or both)

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

rural voters, especially if they were also Mexican-American, would accrue rather minor (and collective) tangible benefits, but these would be more than offset by both tangible and symbolic losses — some quite specific. The rural and Mexican-American political elite had much to lose and no more to gain than any other citizens. Their small gains would be collective, their losses specific to themselves alone. The conflict was, in Dudney’s view, one of an economically-dominant Anglo establishment, seeking to use structural reform to wrest governmental authority from a popularly-based minority ethnic elite whose power rested, in large part, on its control of public office. What Dudney evidently does not accept is the likelihood that what was being challenged was not just the formal structure of authority, but the existing distribution of power in county politics. The Unit Road System would not replace politics with disinterested management. It would, instead, if the reformers’ objectives were realized, effect a transfer of political power from one group to another.

Conclusion

The underlying political nature of the Unit Road System conflict is illuminated by the insightful observations of E. E. Schattschneider (1960) about politics, in general, and by reference to Samuel R Hays’ (1964) empirical investigation of the municipal reform movement. Schattsch¬ neider noted that for every political issue there are two relevant groups — the immediate participants and the audience. The spectators are an integral part of the situation, for the audience “is never really neutral.” The outcome is likely to be determined by the extent to which the spectators become involved. “Every change in the number of participants, every increase or reduction . . . affects the result” (Schattschneider, 1960:2). “The most important strategy of politics is concerned with the scope of conflict” according to Schattschneider (1960:3). He (1960:17) is not moralistic about this strategy: “There is nothing intrinsically good or bad about any given scope of conflict. Whether a large conflict is better than a small conflict depends on what people want to accomplish. A change of scope makes possible a new pattern of competition, a new balance of forces, and a new result.”

From this perspective, the Unit Road System conflict in Jim Wells County appears to have been, at bottom, a battle over the scope of conflict relative to county road policy and administration. The elite Master Planners sought to narrow the scope of conflict by shifting the locus of decision-making from the politically sensitive county commission to a professionally-trained county engineer-manager. The net effect would have been to insulate decision-making from undesirable political pressure.

Hays, who did much to uncover the upper-class social origins of municipal reformers, was aided by his awareness of the danger of

COUNTY UNIT ROAD SYSTEM— ANOTHER VIEW

41

accepting “what people thought and said” as “necessarily an accurate representation of what they did” (1964:169). Hays argued that, in the case of municipal and other progressive reformers, many historians seem to have suspended their usual scholarly skepticism, “taking the reformer’s own description [of their objectives] at face value” (1964:169). In spite of Hays’ efforts, the reform rhetoric is still widely accepted as reality. Dudney’s study, however, offers substantial evidence to the contrary.

The critique of the reform model lays bare the model’s all too human and self-interested soul. It does not, however, wholly disarm the advocates of reformed local government. Some reform advocates may no longer feel free to claim, as comfortably as before, scientific objectivity for their political program. The reformer’s mask of disinterested, nonpolitical, public-spiritedness is now more transparent to knowledge¬ able outsiders. The argument between reformers and their critics, however, is, in the final analysis, both normative and unresolved. Those who, for whatever reasons, prefer more efficient, cost-effective govern¬ ment that will be less responsive to narrow and particular interests, and more responsive to less parochial interests like economic development, will continue to support reformed structures. They will still win converts, especially among upper-class businessmen and middle-class residents of small cities and suburbs. Reform structures do, after all, embody the values and priorities of those constituencies.

Those who feel that government has objectives beyond economic development and the inexpensive provision of services will continue to doubt the superiority of reformed structures. For critics, efficiency and economy are important, but only as instrumental values. The object of local government should be more than mere management. It should be governance — the resolution of conflicts arising from competing values. Governance is inherently political. Indeed, governance is simply politics by another name. A system of government that seeks to expel politics misses the whole point of governance. It is more important that government be human, and that it be responsive and accountable to average citizens (that is, that it be democratic), than that it be efficient and good for business.

This essay has not sought to resolve, once and for all, the dispute over local reform, or even over the Unit Road System in one county. The objective has been, instead, to clarify what the dispute is about. The dispute has been shown to be less one over facts than one over values. It has been revealed, in spite of reformist claims, as a conflict over who should rule, rather than as a choice between politics and management. Ultimately, each community, and each voter, must decide which form of government best satisfies that community’s, or that individual’s, values and needs. This essay will have served its purpose, if it 1) has made the point that there is, indeed, a choice to be made — that not all right and

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THE TEXAS JOURNAL OF SCIENCE— VOU 40, NO. 1, 1988

reason favor “reform”; and 2) has helped inform the process of selection by bringing to bear, on the issue at hand, some of what political science research has revealed about the political implications of the reform model.

Acknowledgments

This article was originally presented at the 89th Annual Meeting of the Texas Academy of Sciences, Kingsville, Texas in March 1986. I am indebted to Ross Dudney, whose field study presented the opportunity for me to rethink and clarify my views on local governmental reform. I also want to thank Vanita Dubose for turning my messy drafts into a typed manuscript suitable for publication.

Literature Cited

Anders, E. 1982. Boss rule in South Texas. Univ. Texas Press, Austin, vii + 319 pp. Childs, R. S. 1952. Civic victories: the story of an unfinished revolution. Harper & Brothers, New York, xvii + 350 pp.

Dahl, R. A. 1984. Modern political analysis. Prentice-Hall, Englewood Cliffs, New Jersey, 4th ed., vii + 157 pp,

Gaus, J. M. 1947. Reflections on public administration. Univ. Alabama Press, i + 153

PP-

Harrigan, J. J. 1981. Political change in the metropolis. Little, Brown, Boston, 2nd ed.,

V + 462 pp.

Hays, S, P. 1964. The politics of reform in municipal government in the progressive era. Pacific Northwest Quart., 55:157-169.

Jones, B. D. 1983. Governing urban America. Little, Brown, Boston, v + 432 pp.

Jones, C. O. 1977. An introduction to the study of public policy. Duxbury Press, North Scituate, Massachusetts, 2nd ed., vii + 258 pp.

Judd, D. R. 1984. The politics of American cities. Little, Brown, Boston, 2nd ed., vii + 423 pp.

Lowi, T. J. 1967. Machine politics old and new. The Public Interest, 9:83-92.

- . 1969. The end of liberalism. Norton, New York, xiv + 322 pp.

Merton, R. K. 1957. Social theory and social structure. The Free Press, New York, rev.ed., xxiii + 702 pp.

Schattschneider, E. E. 1960. The semisovereign people. Holt, Rinehart and Winston, New York, vii + 147 pp.

Shockley, J. S. 1974. Chicano revolt in a Texas town. Univ. Notre Dame Press, London,

V + 302 pp.

Steward, F. M. 1950. A half century of municipal reform: the history of the National Municipal League. Univ. California Press, Berkeley, xi + 289 pp.

VECTOR GEOMETRY OF SPHERES

Ali R. Amir-Moez

Department of Mathematics, Texas Tech University, Lubbock, Texas 79409

Abstract. — The vector equation ||^ — 7II = r, which represents a sphere in a Euclidean space, has been studied by angles and distances with techniques of vector algebra. Key words: vector geometry of spheres.

This article is intended to formulate characterizations of the sphere in a real Euclidean «-space, which are extensions of characterizations of the circle. Two particular ideas are studied, one of which is the sphere as a locus of points with lines of sight to n fixed points are mutually orthogonal, whereas in the other, the sphere is seen to be similar to an ellipsoid with n foci, except that the sum of the squared distance is constant. The latter may be described as having a set of n fixed vectors the first moment of which is zero, and the sphere is the locus of points about which the second moment is of constant magnitude. All results are simple consequences of vector algebra in the Euclidean plane, which easily can be generalized to a ^-dimensional real Euclidean space; in particular the vector form of completing the square is quite useful in obtaining the center and the radius of a sphere.

Notation

A Euclidean space of dimension n will be denoted by Vectors will be denoted by Greek letters and scalars by Latin letters (Amir-Moez, 1978; Amir-Moez and Fredericks, 1983). The inner product of f and 17 is represented by (f, 17). Thus the norm of f will be ||^^|| = (f, Other notation will be introduced whenever needed.

Let a sphere of center C and radius r be given (Fig. 1). A vector equation of this sphere will be

llf-7ll =L (1)

where C is the endpoint of 7 and f ends on the sphere. (Note that the Fig. 1 corresponds to the two-dimensional case.) We may write this equation as

M-yf = r^

or

The Texas Journal of Science, Vol. 40, No. 1, February 1988

44

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

||f||^-2(f, 7)+ (2)

By analogy with the algebra of scalars, we may refer to the recovery of (1) from (2) as completing the square. More generally, the equation

UW^ + aa, a)-b = 0

always can be expressed as

or

Comparing this equation with (1), we may say the center is the endpoint of and the radius is [^||q:||^ —bY\ One has to consider different cases, that is, positive, imaginary, or zero radius.

Representing Spheres by Angles

In R2, we may characterize the circle as follows. Given two fixed points A and B, the locus of P, the vertex of a right angle, the side of which pass through A and P, is a circle of diameter AB. We shall translate this proposition into the language of vector algebra. For simplicity, we shall choose the origin at the midpoint of the line segment AB. Thus to A and B corresponds the endpoints of o; and —a. Let f correspond to P. Then we have

VECTOR GEOMETRY OF SPHERES

45

/3

Figure 2.

(f - a, f + a) = 0, (3)

which implies

llfll = l|a||. (4)

Thus f describes the circle of center 0 and radius ||a||.(Fig. 2).

There are many generalizations of this proposition. A few are given. Let {ai,. . be linearly independent in and f vary so that

- ai, ^ - aj) = 0, i <j, (5)

where ajj is a real number. Then f describes a sphere. One observes that (5) implies

Xaij - I aijit cxi + aj) + S ay (a,-, aj) = 0. (6)

If S aij = 0, then (5) describes a hyperplane; otherwise (5) is a sphere for which the center and radius can be obtained by completing the square in (6). The details are omitted. If in (5) we consider the case that a^- = 1, for all / and y, then we get

Ilf

- _L

n

s =

n{n

1)

-s II a/-a/ir

One may look at a linear combination of spheres as a generalization of (3). In particular, we study the idea for R3, and f vary so that

46

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

r (f - ai, f - ai) - 0

(f - ai, f - a,) = 0 (7)

i (f — a2, f — as) = 0

meaning the endpoint of f is the vertex of right tetrahedron, the three edges of which pass through the endpoints of ai, 0:2, and as (Fig. 3). Note that we have chosen the origin as one of the points on the locus. From (7) we obtain

Ilf 11^ “ y (f, ai + a2 + as) - 0.

Completing the square, we get

Ilf — y (ai + a2 + as) ||^ = y ||ai + a2 + as||^ (8)

We observe that the center of the sphere is the centroid of the triangle defined by the endpoints of ai, a2, and as and the radius is

r = ^11^1 + a2 + asl|.

One can show that this sphere does not pass through the endpoints of ai, a2, and as. In fact, these points are outside the sphere.

A generalization to is similar. Let {ai,...,a„} be set of nonzero orthogonal vectors in R„. Let f vary such that

(f - ay, f - aj) = 0, i <j\ i,j (9)

Then f describes a sphere in R„. From (9) we obtain (2) equations

Uf - it + aj) = 0, / <j, i,j = 1,. . n.

VECTOR GEOMETRY OF SPHERES

47

Adding them we obtain

~ *) ll^ll' - (n - l)(f, I «,) = 0,

2 (=1

which implies

= xad = o

n i=\

or

||f--L S a/||^ = A S Ik, -III

n /=! n /=!

Note that the center is at the centroid of the convex hull of the endpoints of the afs and the radius is

Again one can show that endpoints of a/’s are outside the sphere.

Representing Spheres by Distances First we shall study the idea in R2, and f vary so that

U-ot\\^+U^a\\^^k\ (10)

Then f describes a circle.

To prove this we simply expand (10), and we get

llfll^+ l|a||^-^A:^ = 0.

The reader, by completing the square, may verify that the center is at the origin. The cases of positive, imaginary, and zero radius should be considered.

Now we shall generalize this proposition to R„. Let {ai,. . .,a„.l} be linearly independent in R„, and a„ = — (ai + ... + a„.i). We have chosen the origin at the centroid of the convex hull of {ai,. . .,a„}. Let f vary in R„ so that

48

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

(11)

Then f describes a sphere whose center is at the origin. One can easily show that (11) is equivalent to

11^11' = “

le- 2 Ik, 11^}.

n

n

We shall leave the discussion of cases to the reader.

Some Suggestions

One may study variations on previous propositions. In section 2, one may replace the right angle by a fixed angle or several different angles. In section 3, one may replace the sum by a difference of two sums.

We shall suggest another interesting proposition. (Let {a, P} be linearly independent in R2 and f vary such that

Ilf -all - ^ M-PW b

■=-f,a>0,b>0.

The reader may show that f describes a circle.

One may look into generalizations of this proposition such as the following.

Let {«!,. . be linearly independent in and f vary such that

iif-«iii

where «/ > 0, / = Then f describes a circle or a straight line.

Indeed, generalizations of previous propositions to a unitary space can be studied.

Literature Cited

Amir-Moez, A. R. 1978. Elements of geometry in unitary spaces. Monogr. Undergraduate Math., Guilford Coll., Greensboro, North Carolina, 7:1-54.

Amir-Moez, A. R., and G. A. Fredericks. The convex hull of a set of vectors. Monogr. Undergraduate Math., Guilford Coll., Greensboro, North Carolina, 10:1-36.

FUEL WEIGHT PREDICTION EQUATIONS FOR UNDERSTORY WOODY PLANTS IN EASTERN TEXAS

Hershel C. Reeves and J. David Lenhart

School of Forestry, Stephen F Austin State University, Nacogdoches, Texas, 75962

Abstract. — Equations were developed for predicting total above-ground fuel weight (ovendry in grams) of 19 understory woody plant species in eastern Texas forests, using logarithmic equations and stem basal diameter. Prediction of woody fuel weight can be used to enhance fire intensity estimates under varying fuel moisture and weather conditions. Key words: biomass, fuels; understory species; prediction equations.

Low to moderate intensity fires (wild or prescribed) moving through a forest environment feed on fuel at or near the forest floor, consuming litter, grasses, forbs, and small woody vegetation in the forest understory. Depending on species and burning conditions, living vegetation in the small basal diameter classes (less than 0.6 centimeter) can contribute to the energy output, especially during October through March in eastern Texas forests, when most wildfires occur, and the majority of prescribed fires are planned. If fire managers could accurately evaluate the understory fuel weight present on a designated burn site, they could conduct more efficient and, perhaps, less hazardous prescribed burns (Brown et al. 1982).

Numerous equations for estimating the fuel weight of the small diameter woody plant component of forest ecosystems have been developed for several regions of the United States as Williams and McClenahan (1984) in eastern and southern Ohio; Edwards (1976) in lower Piedmont and Coastal Plain of Georgia; Phillips (1977) in upper Piedmont of Georgia and the mountains of North Carolina; Roussopou- los and Loomis (1979) and Grigal and Ohmann (1977) in northeastern Minnesota; Hitchcock (1978) in Tennessee; Brown and Marsden (1976) and Telfer (1969) in the northern Rocky Mountains; and Franchi et al. (1984) in Alabama and Mississippi.

However, information on understory woody stem fuel weight in eastern Texas forests is not available. Fuel weight prediction equations developed in other regions are not applicable to east Texas because forest conditions affecting understory fuel weight are governed by different plant species, climate, landform, soil, and overstory conditions (Franchi et al., 1984).

In this paper, we present equations to estimate the ovendry weight of the aboveground portion of individual woody stems for 19 species common to the understories of forests in eastern Texas. With this information, along with data on forest litter, fire managers in that region

The Texas Journal of Science, Vol. 40, No. 1, February 1988

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Table 1. Arthmetic means and ranges of variables used to develop biomass prediction equations.

Species	Number of plants	Basal diameter (mm)	Dry weight (gms)
Mean	Range	Mean	Range
Acer rubrum	29	13.2	8-21	63.5	7.6-227.7
Baccharis halimifolia	20	12.2	6-25	68.6	10.6-295.2
Carya tomentosa	21	12.7	5-33	92.6	2.6-528.9
Callicarpa americana	31	10.4	6-17	74.7	4.2-327.7
Cornus florida	39	13.0	5-21	92.2	4.2-250.2
Ilex opaca	31	14.0	7-27	118.4	8.3-519.8
Ilex vomitoria	30	12.2	6-20	126.1	14.5-432.5
Liquidambar styraciflua	35	14.2	6-22	77.6	6.5-249.9
Pinus echinata	29	21.3	12-35	154.6	33.2-438.2
Pinus taeda	32	14.0	7-26	84.7	14.2-421.1
Quercus alba	29	12.2	5-33	99.0	2.3-495.9
Quercus falcata	31	13.2	6-24	81.2	11.7-275.3
Myrica cerifera	34	8.6	3-18	60.6	0.8-256.4
Rhammus caroliniana	27	9.9	4-17	37.6	2.6-147.0
Rhus copallina	30	13.0	5-33	82.4	2.6-528.9
Rhus glabra	29	13.2	7-22	57.1	3.7-195.9
Sassafras albidum	23	13.0	6-22	80.2	3.0-279.2
Vaccinium spp.	22	10.4	6-17	71.0	16.9-172.5
Viburnum dentatum	20	11.2	7-17	85.2	10.2-314.0

can compute total fuel loadings to determine the potential severity of wildfires or estimate the effects of prescribed burns.

Woody Stem Fuel Sampling

Nineteen species commonly occurring in the understory of mixed pine- hardwood forests in eastern Texas were sampled. Data from live stems were collected during the dormant seasons December 1984 to March 1986.

Each selected live woody stem was cut at ground-line. After cutting, basal diameter was measured to the nearest millimeter using a dial-gauge caliper. The above-ground portion of each plant was ovendried and weighed to the nearest 0.1 gram. Table 1 characterizes the data by listing means and ranges for each of the 19 species. Basal diameters for 15 of the 19 species did not exceed 30 mm.

Fuel Weight Prediction

Plottings of observed dry weight (DW) over observed stem basal diameter (D) revealed strong exponential growth trends for each of the 19 species. A logarithmic transformation of the data sets provided excellent linear relationships suitable for simple linear regression analyses. Residual analyses revealed no adverse trends. Fuel weight prediction

FUEL WEIGHT PREDICTION EQUATIONS

51

Table 2. Predicting dry- weight (gms) using basal diameter (mm) of 19 species of understory woody plants in eastern Texas.

Species	Prediction equations
Acer rubrum	DW = 0.03OD^-*"^	86%
Baccharis halimfolia	DW = 0.21OD^-‘”	96%
Cary a tomentosa	DW = 0.034D'-®”	96%
Callicarpa americana	DW = O.OOSD'-’'^	94%
Cornus Jlorida	DW = 0.205D^-'^^	88%
Ilex opaca	DW = 0.056D^-’"’	92%
Ilex vomitoria	DW = 0.176D^-^^°	88%
Liquidambar styraciflua	DW = 0.059D^-®^^	88%
Pinus echinata	DW = 0.08	86%
Pinus taeda	DW = 0J36D^'^°	90%
Quercus alba	DW = 0.073D^-®^^	96%
Quercus falcata	DW = 0.1 76D^-^^^	83%
Myrica cerifera	DW = 0.121D^^^^	96%
Rhammus caroliniana	DW ^ 0.027D^-°'°	98%
Rhus copallina	DW = 0.040D^'^^	94%
Rhus glabra	DW = 0.045D2-^'^	79%
Sassafras albidum	DW = 0.016D^”'	96%
Vaccinium spp.	DW = 0.204D^"^®	90%
Viburnum dentatum	DW = 0.033D'	92%
Composite	DW = 0.096D^-^^'	85%

equations are presented in Table 2 for each of the 19 species. In addition, all data sets for hardwood species were combined into one set, and a composite equation was developed, which should be suitable for undetermined or unspecified components of the forest understory.

Application

Assume that a land manager would like to run a prescribed fire through a mixed pine-hardwood forest somewhere in east Texas. The purpose of the burn might be to reduce potential fuel loads that could contribute to a damaging wildfire. The manager needs an estimate of fuel loading in order to burn in an effective and safe manner.

A recent forest inventory consisting of various size sampling plots and the planar intersect technique provided estimates of overstory woody stem diameters, understory stem diameters, and species composition, and forest floor material, such as litter, forbs and fallen roundwood. The understory woody plant component for our example consisted of eight species plus several undetermined plants. For each category, the average basal diameter and number of stems per hectare was determined (Table 3). The diameter values were substituted into appropriate equations in Table 2. After multiplying by stems per hectare, an estimate of the fuel load for this component of the forest understory was obtained (Table 3).

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Table 3. Average basal diameters, number of stems and dry weight per hectare of selected understory woody species in eastern Texas.

Species	Average basal diameter (mm)	Stems per hectare (number)	Dry material per hectare (kg)
Liquidambar styraciflua	14.2	4600	297
Ilex vomitaria	12.2	3950	410
Myrica cerifera	8.6	5100	176
Cornus florida	13.0	1750	141
Acer rubrum	13.2	950	44
Quercus falcata	12.2	425	22
Vaccinium sp.	10.4	1950	125
Pinus taeda	14.0	2800	193
Miscellaneous	12.8	1225	79
	Total 22,750	1487

The dry weight fuel load of woody stem material of 1487 kilograms per hectare in conjunction with an estimated 8400 kilograms per hectare of forest floor material, enables the experienced forester to calculate the potential energy (heat) release for our example. Actually, full potential energy is not usually realized in a forest fire, due to several stand variables — moisture content of the living and dead fuels, size class and arrangement, weather factors and topography (particularly slope).

The living segment of the fuel complex is seldom totally consumed, but if a sufficient litter layer is present to carry a fire, many of the smaller diameter shrubs, trees, and vines will burn and contribute to the fire’s energy release. Recent fire behavior modeling (Burgan and Rothermel, 1984) with an emphasis on fuels has resulted in an increased understanding of the interacting factors affecting forest fires. However, accurate fire behavior predictions will continue to be rather elusive due to the unlimited combinations of fuel, topography, and weather conditions.

To complete our hypothetical example, let us assume that the landform is interior Coastal Plain. If a prescribed fire (strip headfire) was run through our forest three days after a 12.50-mm rain, litter and duff layers may average 10 and 20 percent moisture content, respectively. Air temperature is 15°C, relative humidity is 25 percent, and wind speed is 9.5 kilometers per hour. Thus we might expect a fuel reduction of at least 40 percent of the 1480 kilograms of woody stem material with basal stem diameters less than 30 mm and about 60 percent of the 8400 kilograms of forest floor material. Reductions would vary under different site and burning conditions.

These estimates are based on a normal distribution of size classes found in understory species for the calculated basal diameters obtained in

FUEL WEIGHT PREDICTION EQUATIONS

53

field sampling. Forest land managers can benefit from better knowledge of part or all of the biomass data.

Literature Cited

Brown, J. K., and M. A. Marsden. 1976. Estimating fuel weights of grasses, forbs and small woody plants. U.S.D.A. For. Serv. Res. Note, INT-210, 11 pp.

Brown, J. K., R. D. Oberheu, and C. D. Johnston. 1982. Handbook for inventorying surface fuels and biomass in the Interior West. U.S.D.A. For. Serv. Gen. Tech. Rep., INT-129, 48 pp.

Burgan, R. E., and R. C. Rothermel. 1984. BEHAVE: Fire behavior prediction and fuel modeling system — fuel subsystem. U.S.D.A. For. Serv. Gen. Tech. Rep., INT-167, 126 PP-

Edwards, M. B., Jr. 1976. Weight prediction for 10 understory species in central Georgia. U.S.D.A. For. Serv. Res. Note, SE-235, 3 pp.

Franchi, B. L., I. W. Savelle, W. F. Watson, and B. J. Stokes. 1984. Predicting biomass of understory stems in the Mississippi and Alabama coastal plain. Mississippi Agric. and For. Exp. Sta. Tech. Bull., 124:1-8.

Grigal, D. F., and L. F. Ohmann. 1977. Biomass estimation for some shrubs from northeastern Minnesota. U.S.D.A. For. Serv. Res. Note, NC-226, 3 pp.

Hitchcock, H. C., HI. 1978. Above-ground tree weight equations for hardwood seedlings and saplings. TAPPI, 61:119-120.

Phillips, D. R. 1977. Total-tree weights and volumes for understory hardwoods. TAPPI, 60:68-71.

Roussopoulos, P. J., and R. M. Loomis. 1979. Weights and dimensional properties of shrubs and small trees of the Great Lakes conifer forests. U.S.D.A. For. Serv. Res. Paper, NC-178, 6 pp.

Telfer, E. S. 1969. Weight-diameter relationships for 22 woody plant species. Canadian J. Bot., 47:1851-1855.

Williams, R. A., and J. R. McClenahen. 1984. Biomass prediction equations for seedlings, sprouts and saplings of ten central hardwood species. For. Sci., 30:523-527.

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THE IMMUNOCHEMISTRY OF BETA-LACTOSIDES

Alfred C. Schram and Javad Paktinat

Department of Mathematics and Physical Sciences and the Killgore Research Center, West Texas State University, Canyon, Texas 79016

Abstract. — The binding of several synthetic lactosides by a chicken anti-lactoside antiserum suggested an antibody combining site complementary to a structure larger than that of a disaccharide. Regions of the antibody molecule adjacent to the lactosyl-binding region appear to be electron deficient. Key words: immunochemistry; lactosides.

A chemically defined immunogenic epitome provides a simple tool for the estimation of the shape and size of the specific antibody combining site, because both structures are complementary. Early work (Beiser et al, 1960; Karush, 1957) indicated that antibody combining sites are complementary to a structure corresponding to the size of a disaccharide unit. Therefore, the lactoside:antilactoside system should provide a convenient method for the estimation of the shape and size of the antibody combining site and of its neighboring region. Several lactosides were synthesized, purified, and tested in a simple competitive inhibition radioimmunoassay. Basically, a limited amount of anti-lactoside antise¬ rum was incubated with a fixed amount of a radiolabeled reference lactoside and various amounts of different lactosides. The more precisely complementary to the antibody combining site, the easier the lactoside would displace the reference lactoside.

Materials and Methods

Lactosides Preparation

The lactosides were prepared from acetobromolactose (mp 147 C — Reithel and Young, 1952) and the appropriate alcohols or sodium phenolates, by adaptation of published methods (Babers and Goebel, 1934; Goebel et al., 1934; Goebel and Babers, 1935; Helferich and Goerdeler, 1940; Karush, 1957; Smith and Van Cleve, 1952). They were recrystallized to a constant melting point from aqueous methanol or aqueous ethanol; their purity was verified by carbohydrate determination on hydrolysates {6M HCl; one hour at 98.5° C) with the anthrone method (Morris, 1948). All were found to be )8-anomers with maximum IR absorption between 892 and 899 cm~' for the jS-glucosidic acetal bond, and between 874 and 880 cm~* for the jS-galactosidic acetal bond. Several of the lactosides crystallized with a molecule of water, which was lost upon heating above 100°C; the loss of water of hydration could be observed during melting point determinations by a change in the crystalline form between 100 and 150°C. The optical rotations of lactosides available in sufficient quantities were measured in 50 percent aqueous methanol (v/v) and are recorded in Table 1. 3-(4’-Lactosylazophenyl)-4-Hydroxy-5-Iodobenzoic Acid-^^^\ (LacIHB)

Ammonium p-hydroxybenzoate (3 x 10~^ mol) was iodinated with 5 mCi of iodine- 125 and 3 x 10~^ mol of carrier iodine. After acidification of the reaction mixture, extraction with diethyl ether, drying over anhydrous Na2S04, and evaporation of the ether in vacuo, the residue was coupled to 3 x 10”^ mol of freshly diazotized /?-aminophenyl lactoside. The

The Texas Journal of Science, Vol. 40, No. 1, February 1988

56

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

product was purified by paper chromatography (Whatman 3MM; 1 -butanol-acetic acid:water = 4:1:1, v/v/v; Rf = 0.67) (Paktinat, 1976). Its label purity was 83.3 percent; a maximum of 84 percent was bound by chicken anti-lactoside antiserum; its specific radioactivity was 3 x lO” cpm/g or 2.1 x 10*'^ cpm/mol.

Antiserum

A six-month-old Black Polish hen was immunized by intramuscular injection of one milligram of porcine gamma globulin coupled to an average of 24 p-azophenyl lactoside groups (Lac24PGG) (Karush 1957), in a 50 percent emulsion of Freund’s complete adjuvant. Booster injections of 0.5 mg Lac24PGG in a 50 percent emulsion of Freund’s incomplete adjuvant were then given at four-week intervals in alternate thighs, over a period of 15 months. Blood (five to 10 milliliters) was obtained by heart puncture at one and three weeks after each booster injection. The sera were frozen until the completion of the injection series. The sera were then tested for anti-lactoside antibody levels. The last 20 sera, which had comparable titers, were pooled, and the pooled antiserum was standardized against an iodine- 125 labeled bovine serum albumin coupled to an average of 11 /?-azophenyl lactoside groups per molecule (LacuBSA), by a quantitative precipitation test. The precipitates, dissolved in O.IM NaOH, were counted for radioactivity (to determine the amount of antigen bound) and the total protein content was determined by the method of Lowry et al. (1951). The amount of antibody in the precipitates was then obtained by difference between the total protein and the amount of precipitated antigen. The values were corrected for non¬ specific precipitation in preimmunication serum controls. The antibody level in the antiserum was determined graphically by extrapolation to 1/f = 0, of the line in a plot of 1/b vs 1/f (b = antibody bound antigen, f = free antigen) (Steward and Petty, 1972a, 1972b). Assuming an antibody molecular size of 170,000 daltons (Schram et al., 1971), the antiserum contained 203 jUg of precipitating anti-lactoside antibody per ml. Fractionation of 0.5 ml of antiserum on Sephadex G-200 (1,5 x 90 cm column, 0.02M trishydroxymethylami- nomethane, 0.1 5Af NaCl, 0.02 percent NaNs; pH 8.6) (Schram et al., 1985), followed by quantitative precipitation of LacnBSA by aliquots of each fraction, indicated that at least 95 percent of the antibody eluted in the gamma globulin region. Linearity of Sips plots (b/ antibody ^ f versus b/ antibody) indicated homogeneity of the antibody population (Kim and Karush, 1974). Treatment of the data in the logarithmic Sips form yielded homogeneity indices in the range of 0.94 to 0.97, close enough to 1.00 to support homogeneity of the antibody population (Keirszenbaum et al., 1969). The rest of the antiserum then was frozen in small vials, each one containing the required amount of antiserum for one inhibition test.

Inhibition Tests

Polycarbonate tubes (13 by 100 mm) were filled with 50 jul of antiserum, appropriate dilutions of inhibitor in pH 7.2 phosphate buffered saline (PBS), and sufficient PBS to make the volume equal to 400 jul. The tubes were mixed and incubated for 15 minutes at 40° C; 100 jul (0.25 m^umol) of LacIHB then were added to each tube, and the exact amount of LacIHB was calculated from the radioactivity of each tube. The tubes were stored overnight at 4°C. An equal volume (500 jul) of 74 percent saturated (NH4)2S04 was added to each tube; the tubes were mixed thoroughly, left to stand 30 minutes at 4°C, and centrifuged for 20 minutes at 2500 g. The supernatants were carefully decanted, the pellets were resuspended in 500 fxl of 37 percent saturated (NH4)2S04, and the tubes were centrifuged a second time (15 minutes, 2500 g). The supernatants were decanted, the pellets were dissolved in 500 jul of O.IM NaOH and the amount of LacIHB bound by the precipitated globulins was determined by the radioactivity of the solutions. Controls of preimmunization serum, and of antiserum without inhibitor were included in each test. The calculated amount of bound LacIHB was corrected for the nonspecific precipitation in the preimmunication serum control. The percent inhibition of precipitation of LacIHB was then plotted versus the log of inhibitor molar concentration in the incubation mixtures, to give

IMMUNOCHEMISTRY OF BETA-LACTOSIDES

57

sigmoidal curves, with an inflection point at 50 percent inhibition. Figure 1 shows such curves for lactose and three other lactosides. For weak inhibitors, it was not possible to obtain a complete curve, because 50 percent inhibition would occur at concentrations higher than 10"^7l/; solubilities and chaotropic dissociation of LacIHB-antibody complexes prevented the use of inhibitor concentrations higher than 10"^ M. The concentration of each inhibitor necessary for a 50 percent inhibition of the binding of LacIHB then was determined graphically and recorded in Table 1. An inhibition index K (K = log [1] ’), allowed a simple comparison between the different compounds tested. This treatment also minimized the experimental errors introduced through radioactivity measurements, dilutions, and other handling procedures.

Results and Discussion

The sequence of reactions studied can be represented by the following equations. The abbreviations are: Ab = antibody; I = lactoside, Ab-I = antibody-lactoside complex; Ab-LacIHB = antibody-LacIHB complex.

Ab + I ^ Ab-I (1)

Ab-I + LacIHB Ab-LacIHB + I (2)

[Ab-LacIHB] is determined by the amount of radiation precipitated upon addition of ammonium sulfate; [LacIHB] is then the difference between the total and the precipitated amounts of radiation.

Table 1 summarizes the results and emphasizes the specificity of the chicken antiserum for the )8-lactosyl hapten. Within the lactosyl moiety, the j8-galactosyl portion is the most important, because even p- nitrophenyl /3-galactoside binds to the antibody. A similar observation was reported by Goebel et al. (1934). It is surprising that galactose itself did not bind significantly at the concentrations used; both a- and P- anomers are present in aqueous solution, and the j8-anomer would be expected to match the deeper portion of the antibody combining site.

The differences between the inhibition indices of the various lactosides tested indicate that the antibody must be complementary to a structure larger than that of a disaccharide. The phenyl group itself strongly increases the binding. But it does not seem to be entirely an effect dependent upon space filling, inasmuch as none of the alkyl lactosides approaches the binding of the phenyl lactosides.

Still, the nature of the binding in the area of the phenyl group must depend on other factors than three-dimensional matching: variously located substituents on the phenyl ring do not prevent binding (that is, o- nitrophenyl lactoside and m-aminophenyl lactosides). A possibility for the binding may be the attraction of the phenyl ring (with a high electron density) to an electron deficient area of the antibody molecule, bordering the site complementary to the lactosyl moiety. Indeed, p-phenylphenyl lactoside binds ten times more rapidly than phenyl lactoside. Both p- aminophenyl and /7-iodophenyl lactosides show a stronger binding than

58

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Figure 1. Inhibition of LacIHB binding by some lactosides (I). [I] = molar concentration of lactoside (bound and free); O, lactose; •, 1 -pentyl lactoside; +, phenyl lactoside; X, p- nitrophenyl lactoside.

phenyl lactoside. But p-nitrophenyl lactoside then should bind less readily than phenyl or p-aminophenyl lactosides, as the nitro group is an electron withdrawing group. To reconcile these observations, it may be assumed that the electronegative oxygen atoms of the nitro group, being in a position similar to that of positions T and 6' of the /?-phenyl group in p-phenylphenyl lactoside, are close to another electron deficient region of the antibody surface. This region must have some degree of flexibility to allow p-nitrophenyl lactoside to bind (steric hindrance should otherwise make the binding much weaker than observed). This assumption could also explain the relatively high binding of 1 -naphthyl lactoside. As expected, LacIHB should show the highest binding, because it is the compound closest in structure to the immunogenic determinant: the azophenyl lactoside determinants in Lac24PGG are bound to tyrosyl residues in the immunogen (Schram, 1970). The differences in inhibition indices of LacIHB and of /?-phenylphenyl lactoside probably are not significant; however, because the antibody structure is limited by the

IMMUNOCHEMISTRY OF BETA-LACTOSIDES

59

Table 1. Fifty percent inhibition indices.

R-/3-OC12HI9010 R =	[I]	,	K’	Melting Point rc)	[«]d
H-	1.4 X	10-^	3.9
CHj-	4.5 X	10“^	4.3	212	-6.3
CHaCH'CH^-	1.4 X	10-^	3.9	192
CHz^CHCHz-	1.2 X	10'"	3.9	168
CH3(CH2)3-	1.0 X	10-^	4.0	172
(CH3)3C-	6.5 X	10-^	3.2	94
CH3(CH2)4-	3.5 X	10"'	4.5	180
CH(CH2)2CH(CH3)-	6.6 X	10"'	4.2	158
CH3(CH2)5-	4.0 X	10"'	4.4	179
CH3(CH2)6-	2.7 X	10"'	4.6	159
CH3(CH2)7-	8.3 X	10"'	4.1	152
CH3(CH2)8-	1.0 X	10"^	4.0	144
CH3(CH2)o-	6.2 X	10"'	4.2	153
CH3(CH2)ii-	1.7 X	10"'	3.8	140
CH3(CH2),5-	4.5 X	10"'	4.3
CH3(CH2)7CH=CH(CH2)7C0HN(CH2)2-	3.2 X	10"'	3.5	157	+2.4
02N ^ ^	1.5 X 3.8 X	10"^ 10"’	5.8 6.4	225 270.5	-21 -83
^ <^'N02	6.7 X	10"^	5.2	205	-50
H2N-<G^	7.2 X	10"’	6.1	247
^ CK>	1.2 X	10"^	5.9	238
1.6 X	10"’	6.8	232
lo- ^	4.8 X	10"’	6.3	242	-38
(CH3)2N^2)"N=N (Lac dye)	3.5 X	10"'	5.5	231
I OH
<^’N=N^Q- (LacIHB)	2.0 X	10"’	6.7	190
HODC ^	7.6 X	10"’	6.1	262
/?-Nitrophenyl )8-Galactoside o-Nitrophenyl /S-Galactoside p-Nitrophenyl ;8-Glucoside Glucose Galactose a-Methyl Glucoside Glucose + Galactose Cellobiose	8.7 X 10'" (4 X 10“^)	3.1 3 3 3 3 3 3 (1.4)^

'Total (bound + free) molar concentration of lactoside to give 50 percent inhibition of the binding of 0.25 mjumol of LacIHB by 50 ijl\ of antiserum.

^The 50 percent inhibition index K = log [I]”'.

^No measureable inhibition at 10”^ M.

■^By extrapolation.

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

shape resulting from the combination of 20 amino acids, the best possible shape may have a higher complementarity to p-phenylphenyl lactoside.

These observations suggest that the antibody combining site could be made of different regions, as diagrammed in Figure 2. Region A should be stereospecific for the )8-lactosyl group and must be the most important part of the combining site. Regions B and C are probably electron- deficient regions; they may be connected by '‘hinge” areas with some degree of flexibility. With a vacant space between the two portions of B and C, each side would tend to repell the other, opening up the comining site, and thus decreasing the “grip” on the lactosyl moiety. Thus lactose should be the worst inhibitor; actually, /-butyl lactoside has a lower inhibition index. The bulk of the /-butyl group may prevent the proper closing of each half of region B. But the inhibition index of this particular lactoside may not be dependable. The melting point seems too low, an indication of impurities in the sample; moreover, this is the only lactoside that decomposed spontaneously within a few weeks. All other lactosides have shown no sign of decomposition after several years of storage at room temperature.

Assuming that regions B and C are electron deficient, a high electron density should be essential on the aglycone portion of the lactosides. Alkyl groups are weak electron donating groups, but their flexibility, their bulk, and the lack of nucleophilic centers at the proper positions may not allow as tight a “grip” by the antibody. It is unlikely that inductive effects of the phenyl group would be felt on the hydroxyl groups of the lactosyl moiety (most probable functional groups involved in the antibody binding); several bonds separate the phenyl group from the lactosyl hydroxyl groups. Thus it does not appear that variations in inhibition indices would be the result of variations in the electronic potential of the lactosyl hydroxyl groups.

A recent report by Geysen et al. (1987) indicated that in the case of a protein antigen (myohemerythrin), the antigen surface areas with higher negative potential were more immunogenic in rabbits. The results presented here involve a synthetic immunogen (azophenyl lactoside) with a high electron density (azophenyl group), and chicken antiserum. Similar conclusions indicate that the antibody response is similar throughout the animal kingdom. This should not be surprising, because all antibodies, being made of the same amino acids and serving the same function, are under the same restrictions imposed by the electronegativities of the small number of atom types of which they are made (C, H, O, N, S).

It should be emphasized that the antibodies used in this study were not monoclonal, and that only one hen supplied the antiserum. It was decided to use the antiserum from a single individual, to prevent individual variations from masking small differences between the binding of slightly different lactosides. The response in other birds might have

IMMUNOCHEMISTRY OF BETA-LACTOSIDES

61

Figure 2. Suggested cross-section of the anti-lactoside antibody combining site and adjacent regions.

been different. The results also could be explained on the basis of a mixture of antibodies of varying specificities, that is, some antibodies complementary for the lactosyl portion, some for a phenyl lactoside and some for p-phenylphenyl lactoside. However, it is unlikely that such an antibody mixture would show a behavior expressed by linearity in a Sips diagram.

Acknowledgments

Parts of this investigation were supported by grants from the Welch Foundation and from the Committee on Organized Research, West Texas State University. We wish to thank Joe M. Angel, Steven J. Bayles, Christopher P. Christenson, James r. Coatney, Retta M. Cunningham, Shu-Jen Hwong, Gary L. Lawrence, Lloyd V. Risley, Gregory R. Unruh, and Jack D. Weaver for the synthesis, purification, and analysis of some of the lactosides.

Literature Cited

Babers, F. H., and W. F. Goebel. 1934. The synthesis of the p-aminophenol ^-glucosides of maltose, lactose, cellobiose, and gentiobiose. J. Biol. Chem., 105:473-480.

Beiser, S. M., G. C. Burke, and S. W. Tanenbaum. 1960. Immunochemical studies on galactosyl-protein conjugates. J. Mol. Biol., 2:125-132.

Geysen, H. M., J. A. Tainer, S. J. Rodda, T. J. Mason, H. Alexander, E. D. Getzoff, and R. A. Lerner. 1987. Chemistry of antibody binding to a protein. Science, 235:1184- 1190.

Goebel, W. F, O. T. Avery, and F H. Babers. 1934. Chemo-immunology studies on conjugated carbohydrate proteins. IX. Specificity of antigens prepared by combining the p-aminophenol glucosides of disaccharides with protein. J. Exp. Med., 60:599-617. Goebel, W. F, and F. H. Babers. 1935. Derivatives of glucuronic acid. V. Synthesis of glucuronides. J. Biol. Chem., 110:707-717.

Helferich, B., and J. Goerdeler. 1940. Synthesis of ;3-d-glucosides. Berichte, 73B:532-542.

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Karush, F. 1957. The interaction of purified anti-betalactoside antibody with haptens. J. Amer. Chem. Soc., 79:3380-3384.

Kierszenbaum, F., J. Dandliker, and W. B. Dandliker. 1969. Investigation of the antigen- antibody reaction by fluorescence polarization. Immunochemistry, 6:125-137.

Kim, Y. D., and F. Karush. 1974. Equine anti-hapten antibody. VIII. Isoelectric fractions of IgM and 7S anti-lactose antibody. Immunochemistry, 11:147-152.

Lowry, O. H., N. J. Rosebrough, A. L. Farr, and R. J. Randall. 1951. Protein measurements with the Folin phenol reagent. J. Biol. Chem., 193:265-275.

Morris, D. L. 1948. Quantitative determination of carbohydrate with Dreywood’s anthrone reagent. Science, 107:254-255.

Paktinat, J. 1976. Avidity of chicken anti-lactoside antibody for synthetic lactosides. Master’s thesis. West Texas State University, Canyon, 20 pp.

Reithel, F. J., and R. G. Young. 1952. Synthesis of a- and )S-lactose 1-phosphate. J. Amer. Chem. Soc., 74:4210-4211.

Schram, A. C. 1970. Heterogeneity of the antigenic centres of albumin toward chicken antibodies. Immunology, 18:7-12.

Schram, A. C., H. F. Gonzales, and C. D. Meador. 1985. Immune response in the bobwhite quail, Colinus virginianus. Texas J. Sci., 37:133-139.

Schram, A. C., S.-J. Hwong, and C. P. Christenson. 1971. Purification of chicken anti- bovine serum albumin antibody. Immunology, 21:637-648.

Smith, F. and J. W. Van Cleve. 1952. A reinvestigation of the preparation of )8-methyl lactoside. J. Amer. Chem. Soc., 74:1912-1913.

Steward, M. W., and R. E. Petty. 1972a. The use of ammonium sulfate globulin precipitation for determination of affinity of anti-protein antibodies in mouse serum. Immunology, 22:747-756.

- . 1972b. The antigen-binding characteristics of antibody pools of different relative

affinity. Immunology, 23:881-887.

PATTERN OF HETEROCHROMATIC VARIATION AND PHYLOGENY IN THE RODENT FAMILY GERBILLIDAE

Mazin B. Qumsiyeh

Department of Pharmacology, St. Jude Children’s Research Hospital, 332 N. Lauderdale, Memphis, Tennessee 38101

Abstract. — Data are presented on the distribution of heterochromatin for species in seven genera of the rodent family Gerbillidae. These data combined with the few published data on C-banding of gerbil chromosomes document a pattern of rich and varied evolution of heterochromatin. The less common types of heterochromatic rearrangements appear to provide more phylogenetic information than the more common types such as short arm additions. A similar situation exists for the euchromatic rearrangements in gerbils. Key words: Gerbillidae; heterochromatin; phylogeny; chromosomal rearrangements.

Constitutive heterochromatin is characterized as staining positive with the C-banding technique, having late DNA replication, and consisting of repetitive nucleotide sequences (Arrighi et al., 1970). In mammals, highly repetitive DNA can account for as little as five percent and as much as 50 percent of the genome size (Hsu and Arrighi, 1971; Miklos et al., 1980; Sherwood and Patton, 1982). The controversy over the function of this repetitive DNA continues with the views ranging from considering this material to be ‘"junk” DNA with little or no function in the genome to being important in chromosomal evolution and speciation (Baker et al., 1987; Cavalier-Smith, 1985; Deininger and Daniels, 1986; Hardman, 1986; Schmid et al., 1975; Sessions, 1986; Yoon and Richardson, 1978).

Recent studies of the rodent family Gerbillidae have documented extensive chromosomal evolution involving Robertsonian rearrangements, tandem fusions, translocations, and peri- and paracentric inversions (Wassif, 1981; Benazzou et al., 1982a, 1982b, 1984; Qumsiyeh, 1986a, 1986b; Qumsiyeh and Chesser, 1988). These publications were concerned with euchromatic rearrangements as revealed by G- or R-bands and paid little attention to heterochromatic changes revealed by C-banding. Herein, I present data on distribution of C-positive material in gerbil chromosomes and examine the relationship between heterochromatic variation and the well-documented phylogenies based on electrophoresis, chromosome G-bands, and morphology for several genera of gerbils.

Methods and Materials

The following gerbil taxa were examined: Gerbillus dasyurus, G. nanus, Gerbillurus paeba, G. vallinus, Tatera robusta, T leucogaster, T. nigricauda, T. afra, T branstii, Desmodillus auricularis, Psammomys obesus, Meriones tristrami, M. crassus, M. unguiculatus, M. shawi, and Sekeetamys calurus. Specimens used in this study were the same as those used previously for the nondifferentially stained (Qumsiyeh et al., 1986), G-

The Texas Journal of Science, Vol. 40, No. 1, February 1988

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

band, and electrophoretic studies (Qumsiyeh, 1986b; Qumsiyeh and Chesser, 1988; Qumsiyeh et al., 1987).

C-bands were obtained by the method of Stefos and Arrighi (1971) as modified by Baker and Qumsiyeh (1988). Identification of chromosomes was done from the G-banded chromosomes and facilitated by a standard numbering system developed by Qumsiyeh (1986b). The data presented are compared to published data on gerbils and other rodents to assess the pattern of heterochromatic variation in the Gerbillidae.

Results

Centromeric heterochromatin was found in all species of gerbils examined. Beyond this, many species are characterized by heterochro¬ matic additions. Both Gerbillurus vallinus and G. paeba share an insertion in chromosome 10 and telometric heterochromatin on the sex chromosomes (Qumsiyeh, 1986b). Additionally, chromosome 33 of G. paeba shows extensive heterochromatin that was “diffused” over most of the chromosome (Fig. 1). Two unidentified acrocentric chromosomes in G. vallinus have small but individually variable heterochromatic short arm additions. Four species of Tetera (afra, brantsii, leucogaster, and nigricauda) share a heterochromatic X-chromosome. Of these, T. afra, T. brantsii, and T. leucogaster acquired heterochromatic short arms on some autosomes (Qumsiyeh, 1986b). Tatera robusta and an unidentified sister taxon from Kenya share heterochromatin on lljlS and 33 but differ in the size and structure of these chromosomes (Qumsiyeh et al., 1987).

Desmodillus auricularis has heterochromatin on chromosome 27/28 and the sex chromosomes (Qumsiyeh, 1986b). Psammomys obesus shows heterochromatin on the sex chromosomes, which are relatively large, and additionally has a variable short arm addition on the small 2p chromosome (Fig. 2). Meriones tristrami and M. crassus acquired numerous heterochromatic short arm additions on several autosomes in addition to diffused heterochromatin (Fig. 3) on the sex chromosomes (Korobitsyna and Korablev, 1980; Qumsiyeh et al., 1986). M. unguicula- tus has a heteroehromatic insertion on chromosome 33 (Fig. 3).

Studies on Gerbillus {sensu lato) show that numerous species have heterochromatic blocks outside of the centromeres (Wassif, 1981; Wahrman et al., 1983; Qumsiyeh et al., 1986, and unpublished). In two species of this genus studied by Viegas-Pequignot et al. (1984), constitutive heterochromatin represented about one half (G. nigeriae) and one third (G. hesperinus) the length of the genome and occurred mainly as short arms and as the proximal part of the long arm in most chromosomes.

Discussion

Heterochromatin in gerbils can be classified into the following basic types (in order of prevalence):

HETEROCHROMATIC VARIATION AND PHYTOGENY OF GERBILS

65

Figure I. Three types of heterochromatic additions observed in Gerbillurus paeba. G- banded (left chromosome of each pair) and C-banded (right) selected chromosomes are shown with C-band positive material being intersitial in 9/10, “diffused” in 33, and telomeric in the X.

1) Centromeric heterochromatin was found in all species of gerbils examined. However, the size of the heterochromatic block surrounding the centromere seems to vary not only between individuals and species but also between chromosomes of the same individual (Figs. 2 and 3).

2) Short arm additions increase the fundamental number but usually do not affect the euchromatic arm to which they attach. This type of heterochromatic addition seems to occur most frequently in taxa with high diploid numbers (60 and more) possessing some fission products (for example, Meriones tristrami, M. crassus, Gerbillurus vallinus, Gerbillus dasyurus). In Psammomys obesus (2n=48), a heterochromatic short arm addition occurred in a polymorphic condition on the smallest acrocentric chromosome (chromosome 2p, Fig. 2).

3) “Diffused” heterochromatin occurring over all or most of the euchromatic arm or arms that are still identifiable by G-banding. This appears to be prevalent in the smallest gerbil linkage groups (numbers 25/26, 27/28, and 33) and in the sex chromosomes (Figs. 1 and 2).

4) Interstitial insertion of heterochromatic bands. This type was found in chromosomes 10 (Fig. 3) in Gerbillurus, 8 in Desmodillus, and 33 in M. unguiculatus (Qumsiyeh 1986b; Qumsiyeh and Chesser, 1988).

5) Telomeric additions were observed only in the sex chromosomes of Gerbillurus paeba and G. vallinus (see Fig. 1 and Qumsiyeh, 1986b).

66

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

%	s r.	i		1 # * - 4
4		* ♦	■, i m ^	t> *1
^ m A		■5 4	-
1 %	M M:.	4 m 'i	t|	f| ■ ; r m
A	m-	1	1	t m ^ •% ^ ♦ .. .
' A * ^ ■w -p	1
t ' ■m- M i	% K V	* 0	^ m ^ V i. 'H * * 1 ,,
	^ *	1	* ♦ 1
B

Figure 2. C-banded chromosomes of Psammomys obesus. C-banded karyotype of a female (A) and a spread from a male with the polymorphic condition for 2p (B). Triangle encloses the biarmed 2p and arrows point to the X and Y (both heterochromatic).

6) Finally, “intercalated” heterochromatin between the sex chromo¬ somes and translocated autosomes has been suggested to play a role in the linkage of activation or inactivation in the sex chromosome-autosome complex (Viegas-Pequignot et ah, 1982; Ratomponirina et ah, 1986). However, this hypothesis was not critically tested and a study by Wahrman et al. (1983) on the sex chromosome-autosome translocations in gerbils failed to support the general conclusions of Ratomponirina et al. (1986).

HETEROCHROMATIC VARIATION AND PHYTOGENY OF GERBILS

67

Figure 3. A, C-banded karyotype of a female from Jordan of Meriones tristrami, a species with variable heterochromatic short arm additions (in this individual, the three chromosomes next to the sex chromosomes); B, C-banded karyotype of M. unguicalatus showing intersitial heterochromatin in chromosome number 33 (fourth pair from the left in the top row).

68

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

When comparing the distribution of heterochromatin revealed by C- banding with the gerbil phylogeny that is now well established based on morphologic, G-band, and electrophoretic analyses (Pavlinov, 1982; Qumsiyeh, 1986b; Qumsiyeh et ah, 1987; Qumsiyeh and Chesser, 1988), the following conclusions become evident. First, centromeric heterochro¬ matin, short arm additions, and “diffused” heterochromatin, although common in some lineages, provide no phylogenetic information. Centromeric heterochromatin occurs in all species and short arm additions occur frequently and independently in various unrelated taxa (for example, Meriones tristrami, Gerbillurus vallinus, and Gerbillus dasyurus). Although some chromosomes (for example, 33, X, and Y) appear to have a tendency to acquire extensive “diffused” heterochro¬ matin, again there is no discernable pattern to their phylogenetic distribution.

Second, changes in fundamental number in gerbils occur both by heterochromatic short arm additions and, less frequently, by pericentric inversions. Pericentric inversions account for seven of 34 euchromatic rearrangements in four genera of rhombomyine gerbils but provide the most important phylogenetic markers for these taxa (Qumsiyeh and Chesser, 1988). By contrast, heterochromatic short arm additions occurred on numerous unrelated autosomes of several taxa (for example, Psammomys obesus and Meriones tristrami). In M. tristrami alone, as few as four and as many as 15 heterochromatic short arm additions occur in various polymorphic conditions in one area of Soviet Transcaucasia (Korobitsyna and Korablev, 1980). Similar variability and abundance for heterochromatic short arms is known for rodents of the families Cricetidae (Sigmodontinae — Baker and Barnett, 1981; Stangl and Baker, 1984), Geomyidae (Patton and Sherwood, 1982; Qumsiyeh et al., 1988), and Muridae (Baverstock et al., 1977, among others). These data suggest that short arm heterochromatic additions are subject to extensive homoplasy and rarely will be useful as phylogenetic markers.

Third, telomeric additions on the X and Y and interstitial heterochro¬ matin in 10 appear to form synapomorphies for Gerbillurus paeba and G. vallinus. These two types of rearrangements were the least frequently observed in gerbil chromosomes. Data from the distribution of euchromatic rearrangements compared to electrophoretic and morpho¬ logic character states in gerbils suggested that the most frequently observed types of rearrangements (Robertsonian) were the least informative and apparently were subject to more homoplasy than originally predicted based on the chromosomal data alone (Qumsiyeh et al., 1987). It appears now that a similar pattern occurs in heterochro¬ matic rearrangements in gerbils; the most frequent types of heterochro¬ matic rearrangements also are apparently subject to extensive homoplasy

HETEROCHROMATIC VARIATION AND PHYLOGENY OF GERBILS

69

and provide little, if any, phylogenetic information compared with the less frequently observed rearrangements.

Acknowledgments

Thanks are due to Robert D. Owen, Karen McBee, and Robert J. Baker for reading an earlier draft of this manuscript. This is part four of a series of reports entitled “Phylogenetic studies of the rodent family Gerbillidae.” For other parts and acknowledgments for specimens used, see Qumsiyeh (1986b), Qumsiyeh and Chesser (1988), and Qumsiyeh et al. (1987).

Literature Cited

Arrighi, F. E., T. C. Hsu, P. Saunders, and C. F. Saunders. 1970. Localization of repetitive DNA in the chromosomes of Microtus argentis by means of in situ hybridization. Chromosoma, 32:224-236.

Baker, R. J., and R. K. Barnett. 1981. Karyotpic orthoselection for addition of heterochromatic short arms in grasshopper mice (Onychomys.-Cricetidae). Southwestern Nat., 26:125-131.

Baker, R. J., and M. B. Qumsiyeh. 1988. Methods of chiropteran mitotic chromosomal studies. In Ecological and behavioral methods for the study of bats (Thomas H. Kunz, ed.), Smithsonian Inst. Press, in press.

Baker, R. J., M. B. Qumsiyeh, and C. S. Hood. 1987. Role of chromosomal banding patterns in understanding mammalian evolution. Pp. 67-96, in Current mammalogy (H. H. Genoways, ed.). Plenum Press, New York, xx + 519 pp.

Baverstock, P. R., C. H. S. Watts, and J. T. Hogarth. 1977. Polymorphism of the X- chromosome, Y-chromosome and autosomes in the Australian hopping mice, Notomys alexis, N. cervinus, and N.fuscus (Rodentia, Muridae). Chromosoma, 61:243-256.

Benazzou, T, E. Viegas-Pequignot, F. Petter, and B. Dutrillaux. 1982a. Phylogenie chromosomique de quarte especes de Meriones (Rongeur, Gerbillidae). Ann. Genet., 25:19-24.

- . 1982b. Phylogenie chromosomique des Gerbillidae. Etude de six Meriones, de

Taterillus gracilis et de Gerbillus tytonis. Ann. Genet., 25:212-217.

Benazzou, T, E. Viegas-Pequignot, M. Prod’Homme, M. Lomard, F. Petter, and B. Dutrilaux. 1984. Phylogenie chromosomique des Gerbilldae. Ill. Etude d’especes des genres Tatera, Taterillus, Psammomys et Pachyuromys. Ann, Genet., 27:17-26.

Cavalier-Smith, T. (ed.). 1985. The evolution of genome size. John Wiley and Sons, New

York, 523pp.

Deininger, P. L., and G. R. Daniels. 1986. The recent evolution of mammalian repetitive DNA elements. Trends in Genetics, 2:76-80.

Hardman, N. 1986. Structure and function of repetitive DNA in eukaryotes. Biochem. J., 234:1-11.

Hsu, T, C., and F. E. Arrighi. 1971. Distribution of constitutive heterochromatin in mammalian chromosomes. Chromosoma, 34:243-253.

Korobitsyna, K. V., and V. P. Korablev. 1980. The interspecific autosome polymorphism of Meriones tristrami Thomas, 1892 (Gerbillinae, Cricetidae, Rodentia). Genetica, 52/ 53:209-221.

Miklos, G. L. G., D. A. Willcocks, and P. R. Baverstock. 1980, Restriction endonuclease and molecular analysis of three rat genomes with special reference to chromosomal rearrangements and speciation. Chromosoma, 76:339-363.

Patton, J. L,, and S. W. Sherwood. 1982. Genome evolution in pocket gophers (genus Thomomys) I. Heterochromatin variation and speciation potential. Chromosoma, 85:149-162.

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Pavlinov, I. Y. 1982. “Phylogeny and classification of the subfamily Gerbillinae,” Byull. Mosk. Obshch. Ispyt. Prorody, Otd. Biol., 87(2): 19-31 (in Russian, English translation no. 1598, Medical Zool. Dept., U.S. NAMRU-3, Cairo, Egypt).

Qumsiyeh, M. B. 1986a. Chromosomal evolution in the rodent family Gerbillidae. Unpublished Ph.D. dissertation, Texas Tech University, Lubbock, 102 pp.

- . 1986b. Phylogenetic studies of the rodent family Gerbillidae: 1. Chromosomal

evolution in the Southern African complex. J. Mamm., 67:680-692.

Qumsiyeh, M. B., and R. K. Chesser. 1988. Rates of protein, chromosome, and morphologic evolution in four genera of Rhombomyine gerbils. Biochem. Syst. Ecol., in press.

Qumsiyeh, M. B., M. J. Hamilton, and D. A. Schlitter. 1987. Problems of using Robertsonian rearrangements in determining monophyly: examples from the genera Tatera and Gerbillurus. Cytogenet. Cell Genet., 44:198-208.

Qumsiyeh, M. B., D. A. Schlitter, and A. M. Disi. 1986. New records and karyotypes of small mammals from Jordan. Z. Saugetierk., 51:139-146.

Qumsiyeh, M. B., C. Sanchez-Hernandez, S. Davis, J. C. Patton, and R. J. Baker. 1988. Chromosomal evolution in Geomys as revealed by G- and C-band analysis. Southwestern Nat., in press.

Ratomponirina, C., E. Viegas-Pequignot, B. Dutrillaux, F. Better, and Y. Rumpler. 1986. Synaptonemal complexes in the Gerbillidae: probable role of intercalated heterochro¬ matin in gonosome-autosome translocations. Cytogenet. Cell Genet., 43:161-167.

Sessions, S. K. 1986. Thoughts on genome size: the controversy continues. Cell, 45:473- 474.

Sherwood, S. W., and J. L. Patton. 1982. Genome evolution in pocket gophers (genus Thomomys) H. Variation in cellular DNA content. Chromosoma, 85:163-179.

Schmid, M., W. Vogel, and W. Krone. 1975. Attraction between centric heterochromatin of human chromosomes. Cytogenet. Cell Genet., 15:66-80.

Stangl, F. B., Jr., and R. J. Baker. 1984. Evolutionary relationships of Peromyscus: congruence in chromosomal, genic, and classical data sets. J. Mamm., 65:643-654.

Stefos, K., and F. E. Arrighi. 1971. Heterochromatic nature of the w chromosome in birds. Exp. Cell Res., 68:228-231.

Viegas-Pequignot, E., T. Benazzou, B. Dutrillaux, and F. Better. 1982. Complex evolution of sex chromosomes in Gerbillidae (Rodentia). Cytogenet. Cell Genet., 34:158- 167.

Viegas-Pequignot, E., T. Benazzou, M. Prod’Homme, and B. Dutrillaux. 1984. Characterization of a very complex constitutive heterochromatin in two Gerbillus species (Rodentia). Chromosoma, 89:42-47.

Wahrman, J., C. Richler, E. Neufeld, and A. Friedmann. 1983. The origin of multiple sex chromosomes in the gerbil Gerbillus gerbillus (Rodentia: Gerbillinae). Cytogenet. Cell. Genet., 35:161-180.

Wassif, S. 1981. Investigations on the relationships of the genera Gerbillus and Dipodillus (Rodentia, Cricetidae) by the use of chromosome banding techniques. Bull. Zool. Soc. Egypt, 31:139-155.

Yoon, J. S., and R. H. Richardson. 1978. A mechanism for chromosomal rearrange¬ ments: the role of heterochromatin and ectopic joining. Genetics, 88:305-316.

NEW POTASSIUM-ARGON DATES OF MAFIC ROCKS WITHIN BIG BEND NATIONAL PARK, TEXAS

Dennis E. Schucker and Dennis O. Nelson

Department of Geology, Sul Ross State University, Alpine. Texas 79832

Abstract. — The Trans-Pecos magmatic province of west Texas constitutes a series of alkaline rocks formed from 48 to 16 m.y. ago. The mafic lava flows of the Chisos Formation and associated intrusions within Big Bend National Park represent some of the older igneous activity within the Trans-Pecos. New potassium-argon age determinations for these mafic rocks combined with major and trace element data indicate that magmas of almost identical chemical composition were generated at different times in the Big Bend region. This suggests a duplication of petrogenetic processes and evolutionary trends through time. In addition, a large variation between a previously published date (Maxwell et al., 1967) and a date determined during this study suggests either that portions of the Alamo Creek Basalt have been erroneously mapped as Ash Spring Basalt, or that the Ash Spring Basalt may be older than suggested by previous workers. Finally, we determined that production of basanite magmas was not confined to early Basin and Range extension (less than 24 m.y. ago) in the Trans-Pecos magmatic province, but that basanites are also some of the oldest igneous rocks in the Big Bend region (46 m.y. ago). Key words: Trans-Pecos, Texas; Big Bend; geochronology; Tertiary.

The Chisos Formation is located in the southern portion of the eastern alkaiic belt of the Trans-Pecos magmatic province, of western Texas. Aspects of the regional geology of the Trans-Pecos magmatic province have been described by Barker (1977), Cameron et al. (1986), Henry and McDowell (1986), and Nelson and Nelson (1986). Members of the Chisos Formation (Alamo Creek Basalt, Ash Spring Basalt, Bee Mountain Basalt, Mule Ear Spring Tuff, and Tule Mountain Trachyandesite) crop out in, and adjacent to, the Big Bend National Park area. Named members are separated by varying thicknesses of volcaniclastic units and unnamed flow units. Descriptions of the general geology of Big Bend National Park can be found in Maxwell et al. (1967).

Henry and McDowell (1986) divided igneous activity within the Trans- Pecos magmatic province into four periods: pre-main phase (48 to 39 m.y.), main phase (38 to 32 m.y.), early tension phase (31 to 27 m.y.), and main Basin and Range phase (24 to 17 m.y.). Eruption of the Alamo Creek Basalt Member of the Chisos Formation occurred during the pre- main phase with the remaining members of the Chisos Formation forming during the main phase of Trans-Pecos magmatism (Henry and McDowell, 1986).

Mafic members of the Chisos Formation, the Alamo Creek Basalt, Ash Spring Basalt, and Bee Mountain Basalt, form three major chemical groups. Several subgroups also have been delineated based on major and trace element relationships (Schucker 1986a, 1986b). In addition, several

The Texas Journal of Science, Vol 40, No. 1, February 1988

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Figure 1. Index map of Big Bend National Park showing locations of samples analyzed during this study: (1) CF8508, Alamo Creek Basalt, large roadcut along Ross Maxwell Scenic Drive (long. 103° 26' 45"; lat. 29° 09' 49"); (2) CF8505, Ash Spring Basalt, small hill east of intersection of main park road and Burro Mesa Pouroff road (long. 103° 24' 24"; lat. 29° 13' 05"); (3) CF8539, Bee Mountain Basalt, Cerro Castellan (long. 103° 30' 58"; lat. 29° 08' 53"); (4) BB8311, Basanite Intrusion, along main park road, near Croton Spring (long. 103° 20' 01"; lat. 29° 20' 13").

outcrops of Alamo Creek Basalt have chemical characteristics similar to Ash Spring Basalts. The chemical similiarity between several Alamo Creek Basalt and Ash Spring Basalt samples could have been caused by a replication of source compositions, melting conditions, and evolutionary paths for these magmas. In order to add support to this theory of replication of magmatic processes through time, several samples were analyzed by the potassium-argon (K-Ar) age method to varify the ages of the members of the Chisos Formation. Four new K-Ar dates were determined during this study, one for each of the mafic members of the Chisos Formation and one analysis of a basanite intrusion within Big Bend National Park (see sample localities on Fig. 1).

Techniques and Data

Potassium-argon analyses were performed on whole-rock samples by Geochron Laboratories, a division of Krueger Enterprises, Inc. Uncertainities on dates determined

DATES OF MAFIC ROCKS, TRANS-PECOS, TEXAS

73

Table 1. Analytical data for K-Ar dates determined during this study.

Sample	K (percent)	^°Ar* (X 10"" mole/ gram)	^°Ar*/^°Ar
CF8539 (Bee Mountain Basalt)
	0.785	3.977	0.630
	0.748	3.863	0.612
Av.	0.767	3.920
CF8505 (Ash Spring Basalt)
	2.988	23.390	0.753
	3.016	22.423	0.768
Av.	3.002	22.906
CF8508 (Alamo Creek Basalt)
	2.739	21.995	0.802
	2.720	21.613	0.662
Av.	2.730	21.805
BB8311 (Basanite intrusion)
	1.075	6.792	0.470
	0.684	6.325	0.341
Av.	0.759 0.839	6.558

'’°Ar* refers to radiogenic ‘^°Ar.

during this study are those reported by Geochron Laboratories. All dates were calculated using the decay constants of Steiger and Jager (1977). Table 1 lists K and Ar analytical data from our four samples. Unlike their silicic counterparts, whole-rock K-Ar dating techniques generally can be performed satisfactorily on relatively fine-grained, unaltered mafic rocks such as those considered in this study (Dalrymple and Lanphere, 1969).

Major and trace element data determined during this study are listed in Table 2. All major elements and Sr, Y, and Nb were analyzed by energy dispersive X-ray fluorescence (XRF). Precision in XRF analyses was determined by multiple analyses of U.S.G.S. standards and is better than five percent for all major elements and trace elements, except MgO, Sr, and Nb, which are better than eight percent. All other trace elements were determined by instrumental neutron activation analysis. Precision, based on replicate analyses of our in-house standard, is better than three percent for Lu, La, Ce, Hf, and Rb; better than five percent for Sm, Eu, Th, Yb, Cs, Sc, Zn, and Ta; better than 10 percent for Ba, Nd, Tb, Cr, Zr, and Co; and better than 12 percent for U.

Discussion

Potassium-argon dates for the mafic units within the Chisos Formation also have been published by Maxwell et al. (1967) and Henry et al. (1986). Table 3 lists all known K-Ar dates for the mafic units of the Chisos Formation.

Alamo Creek Basalt

The reported dates for the Alamo Creek Basalt span a time from about 40 m.y. to 47 m.y. This range indicates either a period of eruption of seven million years for the Alamo Creek Basalt or that some dates are in error. A long period of eruption is possible for the production of Alamo

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Table 2. Major and trace element data for dated samples. Major element oxides as weight percent, trace elements as parts per million.

Sample	CF8539 BMB	CF8505 ASB	CF8508 ACB	BB8311 Basanite
Si02	49.23	54.37	54.84	44.78
AI2O3	15.75	17.06	16.98	16.01
Fe203*	9.94	8.22	7.75	11.58
MgO	8.19	2.02	3.46	7.48
CaO	8.52	4.62	4.66	10.71
Na20	3.38	4.97	4.21	4.72
K2O	0.85	3.62	3.52	1.98
Ti02	1.38	1.84	1.92	1.85
P2O5	0.27	0.77	0.75	1.15
MnO	0.14	0.21	0.20	0.19
Total	97.65	97.70	98.29	100.45
Ba	341	870	1117	578
Cr	29	2	2	260
Cs	5.0	1.8	0.3	2.3
Co	33	5.0	5.0	33
Hf	3.7	10.3	10.2	3.5
Nb	9.4	49	50	17.2
Rb	25.6	66.8	50.7	63
Sc	25	3.3	3.2	23
Sr	514	702	973	—
Ta	0.6	5.4	5.3	1.3
Th	1.7	8.1	8.5	5.5
U	0.7	6.1	6.7	2.0
Y	33	48	51	25
Zn	94	132	125	93
Zr	170	516	513	180
La	15	65	65	35
Ce	35	129	128	75
Nd	21	58	59	40
Sm	4.4	10.0	10.1	9.3
Eu	1.5	3.1	3.1	2.6
Tb	1.0	1.7	1.7	1.4
Yb	2.6	3.7	3.8	2.0
Lu	0.36	0.50	0.49	0.28

*Fe203 Total iron as Fe203

Creek Basalt lavas because it is composed of at least seven flow units that erupted from at least two separate source vents (Stewart, 1984). We collected our Alamo Creek Basalt sample, CF8508, in the large road cut along the Ross Maxwell Scenic Drive (Fig. 1). This sample is a trachybasalt (Table 2) according to the nomenclature of Irvine and Baragar (1971). It was selected for dating because of chemical similarities to Ash Spring Basalt samples (Schucker, 1986a, 1986b). A sample having chemistry similar to Ash Spring Basalt units was chosen in an attempt to

DATES OF MAFIC ROCKS, TRANS-PECOS, TEXAS

75

Table 3. All known K-Ar dates for the mafic flow units within the Chisos Formation and the date obtained for a basanite intrusion during this study.

		K-Ar date (m.y.)
Sample designation	Maxwell et al. (1967)	Henry et al. (1986)	This study
Bee Mountain	23.1 + 1.2	34.5 + 1.8	29.9 ± 1.7
Basalt
Ash Spring	34.5 + 1.7	—	44.5 ± 1.8
Basalt
Alamo Creek	43.2 ± 3.1	46.1 ± 3.1	46.5 + 1.9
Basalt Basanite instrusion	43.8 ± n.r. 39.7 ± n.r.	46.9 ± 1.1	45.5 ± 2.3

n.r. indicates that uncertainties are not reported.

prove the production of compositionally similar magmas through time in the Big Bend region. The resulting date, 46.5 ± 1.9 m.y., supports stratigraphic data indicating that this sample is a flow unit from the Alamo Creek Basalt. In addition, this age for a sample of Alamo Creek Basalt having Ash Spring chemistry suggests that similar magmas were produced and evolved along similar trends through time.

Ash Spring Basalt

Two K-Ar determinations are now available for the Ash Spring Basalt. A whole-rock analysis by Maxwell et al. (1967), 34.5 ± 1.7 m.y., and our new data (Table 3), 44.5 ± 1.8 m.y. This difference may be explained in one or more ways. The sample analyzed by Maxwell et al. (1967) may have suffered argon loss or our sample may have excess argon, or some of the Alamo Creek Basalt may have been incorrectly mapped by Maxwell et al. (1967) as Ash Spring Basalt. Sample CF8505, a trachybasalt (Table 2), was used for the K-Ar analysis of the Ash Spring Basalt. This sample, collected south of Burro Mesa Pouroff (Fig. 1), was chosen for analyses because it is some of the least weathered basalt that is mapped as Ash Spring Basalt. Alteration and weathering can greatly affect K-Ar analyses. Therefore, it is critical that the least weathered samples are analyzed. At this locality, lava crops out as small isolated hills surrounded by Quaternary alluvium, and detailed stratigraphic control is lacking. Inasmuch as faulting is present in areas adjacent to this location, faults, possibly covered by alluvium, may have disrupted the stratigraphy of the Chisos Formation in this area. Thus, it is possible that these outcrops are Alamo Creel Basalt, not Ash Spring Basalt as mapped by Maxwell et al. (1967). In addition, the basalt exposed in these outcrops has megascopic and petrographic characteristics similr to several of the Alamo Creek Basalt lavas (Schucker, 1986b), and before the K-Ar analyses it was thought that this sample would help to prove that similar

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

magmas were generated during Alamo Creek time (—45 m.y.) and Ash Spring time (34 m.y.). If this sample is actually Ash Spring Basalt (Maxwell et al. 1967), our date suggests that the Ash Spring Basalt is much older than previously thought. Ash Spring Basalt occurs much lower in the Chisos section than the overlying named members and at most locations is stratigraphically closer to the Alamo Creek Basalt (46.5 ± 1.9 m.y., this study) than it is to the overlying Bee Mountain Basalt (34.5 ± 1.8 m.y., Henry et al., 1986). Although stratigraphy may suggest an older age for the Ash Spring Basalt, stratigraphic position cannot be used as unquestionable support because several unconformities occur within the Chisos Formation. Based on the above data, we believe that our sample may have been erroneously mapped by Maxwell et al. (1967), although additional analyses are needed on the Ash Spring Basalt before the extent of this problem can be determined.

Bee Mountain Basalt

A date of 29.9 + 1.7 m.y. for the Bee Mountain Basalt was obtained from sample CF8539 (Table 2), a hypersthene-normative alkali basalt (using the classifications of Irvine and Baragar (1971) and Miyashiro (1978)). It was collected on Cerro Castellan in the southern portion of Big Bend National Park (Fig. 1). Although much of the outcrop on the lower slopes of Cerro Castellan is weathered and contains abundant secondary silica and calcite, our sample used for K-Ar analysis was a fresh, dense, black, medium-grained basalt collected near the stratigraphic center of the outcrop.

Two previous K-Ar determinations are available for the Bee Mountain Basalt. Maxwell et al. (1967) obtained a date of 23.1 ± 1.2 m.y. They stated that this date is anomalously young when compared to dates obtained for overlying units, and probably resulted from Ar leakage from the altered groundmass in the sample (Maxwell et al., 1967). The only other K-Ar determination of the Bee Mountain is 34.5 + 1.8 m.y. (Henry et al. 1986). Stratigraphic position and K-Ar determinations of units above and below the Bee Mountain Basalt (Henry et al., 1986) indicate that the actual age of the Bee Mountain Basalt is probably 30-35 m.y. Basanite Intrusion

Sample BB83-11 is a silica-undersaturated mafic rock (Table 2) collected near Croton Springs Road (Fig. 1). The rock contains approximately 18 percent normative nepheline and is classified as a basanite. Basanites occur elsewhere in the Big Bend area (Schucker 1986b; Scheiffer and Nelson, 1981) and in the Davis Mountains of western Texas (Ward and Nelson, 1987). However, it is not clear whether or not these silica-undersaturated, nepheline-normative magmas were restricted to a particular period of igneous activity or were produced throughout the evolution of the Trans-Pecos magmatic province. Published K-Ar dates (Henry et al., 1986) and the observation that many

DATES OF MAFIC ROCKS, TRANS-PECOS, TEXAS

77

of the mafic nepheline-nomative rocks occur as northwest-trending dikes suggest that the bulk of these magmas were emplaced 24 to 17 m.y., during Basin and Range faulting (Henry and McDowell, 1986). The result of our work, 45.5 ± 2.3 m.y. for the basanite near Croton Springs (BB83-11) clearly indicates that basanite production was not restricted to the most recent episode of magmatic activity in the Trans-Pecos province, but also occurred during the oldest phase (pre-main phase of Henry and McDowell, 1986) of igneous activity within this region.

Summary and Conclusions

The Alamo Creek Basalt (46.5 + 1.9 m.y.) analyzed during this study has chemical characteristics similar to Ash Spring Basalt unit. If the Ash Spring Basalt is 34 m.y., (Maxwell et al. 1967), then our new data, combined with major and trace-element data from Schucker (1986b), suggest magmas were generated and evolved by similar magmatic processes in the Big Bend region of Texas 46 m.y. and 34 m.y. ago.

Our Ash Spring Basalt sample, as mapped by Maxwell et al. (1967), was determined to be 44.5 ± 1.8 m.y. indicating that some of the Alamo Creek Basalt may have been erroneously mapped as Ash Spring Basalt by previous workers. If our interpretation of the data is wrong and the outcrop was mapped correctly by Maxwell and others (1967) as Ash Spring Basalt, data obtained during this study suggests that the Ash Spring Basalt is older than previously reported. Additional K-Ar analyses are needed on the Ash Spring Basalt before this problem can be resolved.

Finally, the basanite date of 46 m.y. indicates that the production of nepheline-normative, silica-undersaturated mafic magmas was not con¬ fined to Basin and Range magmtism (24 to 17 m.y. ago), but also occurred during the oldest period of magmatic activity in the Trans-Pecos region.

Several problems need additional examination. Additional Alamo Creek Basalt samples need to be analyzed to place better constraints on the duration of volcanic activity from the vents that produced these flows. Samples from the Ash Spring Basalt need to be analyzed to determine if Ash Spring flow units are 34.5 m.y. (Maxwell et al. 1967) and several outcrops of the Alamo Creek Basalt were erroneously mapped as Ash Spring, or if the date of Maxwell et al. (1967) is in error and the Ash Spring Basalt is actually older than previously thought. In addition, the Bee Mountain Basalt contains numerous flow units that have not been dated. Analyses of these units may place better constraints on the age of the Bee Mountain Basalt lavas.

Acknowledgments

We thank the National Park Service for permission to collect samples in Big Bend National Park. This project was supported in part by a Grant-in-Aid of Research from

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Sigma Xi. Additional funding was supplied by a reactor sharing grant from the Nuclear Science Center, Texas A&M University, Chihuahuan Desert Research funds provided by the Texas Legislature, and from the National Science Foundation (RII-8504808). We also thank K. A. Foland for reviewing an earlier version of this manuscript.

Literature Cited

Barker, D. S. 1977. Northern Trans-Pecos magmatic province: introduction and comparison with the Kenya Rift. Geol. Soc. Amer. Bull., 88:1421-1427.

Cameron, M., K. L. Cameron, and M. F. Carman, Jr. 1986. Alkaline rocks in the Terlingua-Big Bend area of Trans-Pecos Texas. Pp. 123-142, in Igneous geology of Trans-Pecos, Texas (J. G. Price et al., eds.). Bureau Econ. Geol., Univ. Texas, Guidebook, 23:1-360.

Dalrymple, G. B., and M. A. Lanphere. 1969. Potassium-argon dating. W. H. Freeman, San Francisco, 258 pp.

Henry, C. D., and F. W. McDowell. 1986. Geochronology of the Tertiary volcanic field, Trans-Pecos, Texas. Pp. 99-122, in igneous geology of Trans-Pecos, Texas. (J. G. Price et al., eds.). Bureau Econ. Geol., Univ. Texas, Guidebook, 23:1-360.

Henry, C. D., F. W. McDowell, J. G. Price, and R. C. Smyth. 1986. Compilation of potassium-argon ages of Tertiary igneous rocks, Trans-Pecos, Texas. Bureau Econ. Geol., Univ. Texas., Geol. Circ., 86-2: 34 pp.

Irvine, T. N., and W. R. A. Baragar. 1971. A guide to the chemical classification of the common volcanic rocks. Canadian J. Earth Sci., 8:523-548.

Maxwell, R. A., J. T. Lonsdale, R. T. Hazzard, and J. A. Wilson. 1967. Geology of Big Bend National Park, Texas. Univ. Texas Publ., 6711:1-320.

Miyashiro, A. 1978. Nature of alkalic volcanic rock series. Contrib. Mineral. Petrol., 66:91-104.

Nelson, K. L., and D. O. Nelson. 1986. Magmatic evolution of the Van Horn Mountains Caldera and comparison with alkaline magmatism in the eastern Trans-Pecos magmatic belt. West Texas. Pp. 164-177, in Igneous geoology of Trans-Pecos Texas (J. G. Price et al., eds.). Bureau Econ. Geol., Univ. Texas, Guidebook, 23:1-360.

Schieffer, J. H., and D. O. Nelson. 1981. Petrology and geochemistry of megacrysts, zenoliths, and their host basalts from the Terlingua Mercury District of West Texas. Geol. Soc. Amer. Abs. with Prog., 13:547.

Schucker, D. E. 1986a. Mafic rocks of the Chisos Formation, west Texas: evidence for multiple source regions. Geol. Soc. Amer. Abs. with Prog., 18:264.

- . 1986b. Geochemistry and Petrogenesis of the Mafic Flow Units within the Chisos

Formation, Big Bend National Park, Texas. Unpublished M.S. thesis, Sul Ross State Univ., Alpine, Texas, 206 pp.

Steiger, R. H., and E. Jager. 1977. Subcommission on geochronology: convention on the use of decay constants in geo-cosmochronology. Earth Planet. Sci. Lett., 36:359-362.

Stewart, R. M. 1984. Stratigraphy and petrology of the Alamo Creek Basalt, Big Bend National Park, Brewster County, Texas. Unpublished M.S. thesis, Univ. Houston, Houston, 186 pp.

Ward, R. L., and D. O. Nelson. 1987. Trace element and oxygen isotopic evidence for the origin of quartz-trachytes and rhyolites, northern Davis Mountains, West Texas. Geol. Soc. Amer. Abs. with Prog., 19:341.

Present address of Schucker: Department of Geology and Mineralogy, Mendenhall

Laboratory, The Ohio State University, Columbus, Ohio 43210.

CORROSION OF LOW-CARBON STEEL IN 1.0 M HCl INHIBITED WITH OCTLYAMINE AND QUINOLINE

Steven G. Spears, Larry G. Spears, and Joycelyn C. Spears

Department of Chemistry, Rice University, Houston, Texas 77005, Department of Natural Sciences, University of Houston- Downtown, Houston, Texas 77002, and Science Department, Cypress Creek High School, Houston, Texas 77069

Abstract. — The corrosion rates and Eo.c. measurements of low-carbon steel at 24° C, 34° C, and 44° C in 1.0 M HCl, with and without varying amounts of octylamine and quinoline, were measured. Based on these data, values for the activation energy (Ea),AG, and AS of the corrosion reaction were determined. In addition, Langmuir, Tempkin, and Freundlich adsorption isotherms were determined. Using the Langmuir isotherms, values for the equilibrium constant, AGa, and ASa of the adsorption/ desorption reaction for the inhibitors were determined. Using corrosion rate measurements, values for the heats of adsorption and surface residence times of the inhibitors were determined. Key words: corrosion inhibitors; iron corrosion; adsorption isotherms; thermodynamic values; kinetic values.

Many papers have been published related to the inhibition of the corrosion of iron in HCl solutions via the use of organic inhibitors. Octylamine and quinoline were chosen for this study because they are representative of two large groups of amine inhibitors commonly used to inhibit the corrosion of iron in strong acid environments. The purpose of this investigation was to determine a variety of adsorption, kinetic, and thermodynamic properties associated with the inhibition of the iron corrosion reaction in HCl using these inhibitors, and to attempt to correlate them with the effectiveness of the inhibitor.

Experiment

The low-carbon steel used during this study was in sheet form of 0.914 mm thickness (20 gauge). Surface area of the exposed test samples was approximately 10 square centimeters. Each corrosion rate measurement was done in fresh, well stirred, 1.0 M HCl. Cell temperatures were maintained at + 0.5° C using a temperature regulated water bath. Freshly prepared Ag/AgCl electrodes and a Keithley Model 610-C electrometer were used for steady-state potential measurements. The two inhibitors tested were of research grade purity. The steel test strips were polished with 600-grit carbide paper, cleaned with acetone, and stored in a dessicator until ready for use. All mass measurements were made using an analytical balance. Corrosion rates were determined after the metal samples had been immersed in the test solutions for two hours.

Results

As mentioned above, quinoline and octylamine were selected for this study because they were representative of two large groups of aliphatic

The Texas Journal of Science, Vol. 40, No. I, February 1988

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THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

and aromatic amine inhibitors. These compounds differ significantly in their basic properties; the Kb for quinoline is 7.94 x and for

octylamine it is 4.47 x 10 "^. Thus octylamine should be considered as a stronger nitrogen-containing base than quinoline. Using an Ealing CPK model atom set, in a manner similar to that used by Hackerman et al. (1962), the maximum surface area coverage for a molecule of quinoline was estimated to be 1.54 x 10~^cm^ and for octylamine, 8.04 x 10~^cm^.

Table 1 lists the average corrosion rates for the low carbon steel at 24° C, 34° C, and 44° C in uninhibited and inhibited 1.0 M HCl and the graphically-determined values of the Arrhenius activation energy (Ea) for the corrosion reaction. To determine Ea, it was assumed that the rate of the corrosion reaction (C.R.) can be expressed using the equation

C.R. = k[Af[B]” . . . , (1)

where k equals reaction rate constant at a particular temperature; [A], [B], and so forth, are the concentrations of the reactants; and “m”, “n”, and so forth are the orders with respect to each particular reactant. The Arrhenius expression states that

k = , (2)

where R = 8.31 J/mol-K, T = degrees Kelvin, and A = the pre¬ exponential factor (a constant for a particular reaction). Substituting equation (1) into (2)

C.R. = ([Af[B]" . . .)Ae'‘= (3)

or

C.R. = (4)

where A’ is also constant for a particular reaction if the reactant concentrations are the same. Thus in order to determine Ea, it is not necessary that one determine values for the order of each reactant. If a plot of ln(C.R.) vs. 1/T is linear, the slope will be equal to -Ea/R, and from this the value of Ea is determined.

For an electrochemical reaction, it is well known that

AGrx = -nFErx, (5)

where AGrx = change in free energy for the reaction at a particular temperature; F = Faraday’s constant (96500 coulombs per equivalent); n = number of equivalents (moles of electrons being transferred in the

Table 1. Kinetic parameters for low-carbon steel in uninhibited and inhibited I.O M HCl.

CORROSION OF LOW-CARBON STEEL

81

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82

THE TEXAS JOURNAL OF SCIENCE— VOL. 40, NO. 1, 1988

Table 2. Summary of Eo.c. values for low-carbon steel in uninhibited and inhibited 1.0 M HCl.

Solution		Eo.c.vs Ag/AgCl (V)		, Eo.c. slope Slope intercept (V) AE/AT(v/°C)
7°C	20° C	30° C	40° C
Uninhibited	-.401	-.424	-.452	-.464	-.385	-.00220
.000 IM Octylamine	-.399	-.426	-.449	-.461	-.384	-.00209
.00 IM Octylamine	-.398	-.424	-.477	-.459	-.383	-.00206
.OIM Octylamine	-.396	-.420	-.441	-.455	-.382	-.00197
.000 IM Quinoline	-.390	-.399	-.429	-.457	-.367	-.00221
.00 IM Quinoline	-.386	-.394	-.425	-.454	-.362	-.00224
.OIM Quinoline	-.368	-.384	-.416	-.444	-.342	-.00250

reaction, which for this study was assumed to be = 2); and Erx = voltage (IV = IJ/coul), or potential of the reaction with respect to the standard hydrogen electrode (SHE). For such a reaction, AS (change in entropy) can be determined at constant pressure (Adamson, 1979), using the relationships

AS = nF(A E/ AT)p. (6)

Table 2 lists the corrosion potentials (Eo.c.) that were measured in uninhibited and inhibited HCl. In order to use equation (5) to calculate the values for AG shown in Table 3, it was necessary to convert the Eo.c. measurements in Table 2 to values with respect to the SHE using the relationship

EAg/AgCl = E°Ag/AgCl -2-303 RT ,og y±Uc,-,

(7)

where (Bard et al., 1985)

E%g/Agci=0.23659 V - 4.8564 X lO'^T - 3.4205 x lO'V (8)

and 7+ is 0.809 (Bromberg, 1984) for 1.0 M HCl, the Mci- = 1, and the temperature is expressed in degrees centigrade. To convert the Eo.c. measurements in Table 2 to values with respect to the SHE, the adjusted values for the Ag/AgCl electrode were added to the measured Eo.c. values. The values shown for AS in Table 3 were calculated using the slope values that were obtained from plotting Eo.c. vs T and are listed in Table 2. For these calculations the negative sign of the slope must be changed to a positive one to coincide with the standard sign convention for thermodynamic values.

The sorption properties of organic inhibitors in aqueous solutions on metal substrates have been studied in a number of ways. Three

CORROSION OF LOW=CARBON STEEL

83

Table 3. Summary of AS and AG Values for the corrosion of low-carbon steel in TO M HCL