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- Biodiversity of Dragonflies and Damselflies (Odonata) of the South-Central Nearctic and Adjacent Neotropical Biotic Provinces
- The south-central United States serves as an important biogeographical link and dispersal corridor between Nearctic and Neotropical elements of western hemisphere odonate faunas. Its species are reasonably well known because of substantial collections, but there has been no concerted effort to document the extent of biodiversity and possible geographic affinities of dragonflies and damselflies of this region. The recent discoveries of Argia leonorae Garrison, Gomphus gonzalezi Dunkle and Erpetogomphus heterodon Garrison from southern and western Texas and northern Mexico suggest that Odonata species remain to be discovered in this area, particularly from far south Texas and northern Mexico. I have documented a total of 12,515 records of Odonata found in 408 counties within the south-central U.S. A total of 73 species of damselflies and 160 species of dragonflies was revealed in the region. The 233 (197 in Texas) Odonata species are distributed among 10 families and 66 genera. Illustrated family, generic, and species-level keys are provided. Since the beginning of this work in the Fall of 1993, one species has been added each to the Louisiana and Oklahoma faunas, and 12 species have been added, previously unreported from Texas, including four new to the U.S. The area of highest Odonata biodiversity overall (161 spp.) is in the Austroriparian biotic province. The greatest degree of faunal similarity between the south-central U.S. and other intra-continental regions was observed for the eastern (64%) United States. Diversity is a function of area, and as expected, the numbers of breeding birds and Odonata, in each contiguous U.S. state are positively correlated (r=0.376, n=33, p=0.031). There is, however, no strong correlation between land area and species diversity within the region, but those natural biotic provinces (Austroriparian, Texan, Balconian) where aquatic systems and topographic heterogeneity are the greatest provide a broader spectrum of potential Odonata habitats and …
- A Study of the Bacterial Flora of Food Utensils in Hardin College Cafeteria and Twenty-Five Eating Establishments in Wichita Falls, Texas
- The problem of this thesis consists primarily of a bacteriological survey of the eating utensils of Hardin College Cafeteria and twenty-five other eating establishments in the city of Wichita Falls, Texas. This investigation was made primarily with reference to a determination of the possible presence of typhoid and related organisms, and secondarily to an investigation of the actual presence of those bacterial organisms associated with the more common outbreaks of food poisoning.
- Degradation of Phenolic Acids by Azotobacter Species Isolated from Sorghum Fields
- Sorghum plants excrete phenolic acids which reduce subsequent crop yields. These acids accumulate in field soil by combining with soil and clay particles to form stable complexes which remain until degraded by bacterial metabolism. The amount of phenolic acids in soil samples were obtained by gas chromatography measurements, while Azotobacter populations were obtained by plate counts in 40 sorghum field samples from Denton County, Texas. One can conclude that increasing the Azotobacter population in the soil increased the degradation rate of phenolic acids proportionally. It is proposed that seed inoculation will introduce selected strains of Azotobacter into the soil. The presence of Azotobacter should increase crop size in subsequent plantings.
- Food Habits and Dietary Overlap of Four Species of Rodents from the Mesquite Plains of Texas
- The coexistence of Dipodomys ordii and Perognathus hispidus with Peromyscus maniculatus and Reithrodontomys montanus was studied in a grassland association of central Texas. The food habits of these species were compared with information from habitat vegetation analysis in an effort to determine food selectivity and the amount and importance of niche overlap and competition among these rodents.
- Microbiotic Cycles in Lake Hefner
- The purposes of this paper are 1) to determine the microbiotic cycles which occur in Lake Hefner in order to form a basis for ascertaining the effects of future additions of evaporation control chemicals on the biological life of this reservoir, and 2) to make a generalization as to the microbiotic cycles which might occur in Southwestern reservoirs.
- Callibaetis Floridanus (Ephemeroptera: Baetidae) Life History and Production in a West Texas Playa
- A life history study of Callibaetis floridanus was conducted over the wet cycle of a playa on the Southern High Plains of Texas from June through September 1995.
- Food, Feeding Selectivity, and Ecological Efficiencies of Fundulus notatus (Rafinesque) (Osteichthyes; Cyprinodontidae)
- This study was made to further define the trophic dynamics of Fundulus notatus by determining its ration composition under natural conditions, measuring feeding selectivity under various laboratory conditions of prey-species composition and availability, and determining the efficiencies with which F. notatus utilizes ingested chironomid larvae.
- The Influence of a Return of Native Grasslands upon the Ecology and Distribution of Small Rodents in Big Bend National Park
- In the southwestern United States there is a delicate balance between the existing grasslands and the rodent fauna. The purpose of this investigation was to determine the influence of secondary succession of native grasslands upon the ecology and distribution of small rodents. Two methods of determining the rodent species were plot quadrates and trap lines using Sherman live traps.
- Evaluation of a Constructed Wetland to Reduce Toxicity from Diazinon at the Pecan Creek Wastewater Treatment Plant, Denton, TX
- The City of Denton Pecan Creek Wastewater Treatment Facility has periodically failed effluent toxicity testing. A Toxicity Identification Evaluation has determined that Diazinon in the effluent is contributing to the observed toxicity. Chlorpyrifos is also implicated as a factor. The City of Denton constructed a half acre experimental wetland to remove Diazinon related toxicity. Results from spiking and microcosm experiments indicate that the wetland can reduce the Diazinon.
- Analysis of Phytoplankton Responses to Water Chemistry Dynamics in a Moderately Eutrophic North Texas Reservoir
- Canonical correspondence analysis (CCA) was used to explore relationships between measured environmental variables and in situ phytoplankton communities in a moderately eutrophic North Texas Reservoir.
- The Use of Similarity Indicies to Assess the Spatial Differences of the Phytoplankton Communities in Lake Ray Roberts, Texas
- A study of the phytoplankton communities of Lake Ray Roberts was conducted at three sampling sites on two sampling dates during the summer of 1995, assessing both community structure and chlorophyll a concentrations. Eight similarity indices were then used to characterize and compare the communities of these sites. Both community similarity and chlorophyll a concentrations were evaluated using a minimum detectable difference equation to determine the amount of change that must occur in these parameters in order to be deemed statistically significant. The Bray-Curtis Index was shown to be the most adequate index evaluated, and was subsequently used in conjunction with bootstrap analysis to determine the similarity between the three sampling sites.
- Bacterial Survey of Representative Wells of Canyon, Texas, with Special Emphasis on Sanitation
- The problem of this thesis consists of a bacterial analysis of twenty-five representative wells within a radius of thirty miles of Canyon, Texas. An attempt has been made to determine the possible presence of the typhoid organism in these wells.
- Evaluating Fish Impingement and Entrainment at the Comanche Peak Steam Electric Station
- This study was designed to determine if impingement and entrainment by cooling water intake at the Comanche Peak Steam Electric Station have an adverse impact upon the Squaw Creek Reservoir fish population. The yearly impingement of fish was estimated to be 262,994 of 14 species. The threadfin shad (Dorosoma petenense) accounted for 96% of this total. Entrainment of eggs and larvae for a five month period was estimated to be 15,989,987 and 42,448,794 respectively. Two fish population studies were performed on Squaw Creek Reservoir to help assess impact. It was determined that the losses due to impingement and entrainment have no adverse impact upon the fish population of Squaw Creek Reservoir.
- A Study of a Selected Group of Science Related Characteristics of Non-Science Majors
- The purpose of this study is to gather information related to the characteristics of two groups of undergraduate non-science majors; namely, those students who once considered science as a career and subsequently changed to a non-science major and those who have never considered a career in science. It is frequently observed that children in the elementary school have an intense interest in science. One of the principal concerns of this study is how and for what reasons has the interest in science changed between elementary school and college? It is also the purpose of this study to gather information related to the attitudes of these college students toward the science courses they have had in high school and toward their science teachers. In attempting to arrive at an answer, the group who once considered a science career and those who have never considered an occupational choice in a field of science will be compared in the following areas: 1. General information such as sex, age, size of high school attended, rank within their graduating classes, college classification and military experiences. 2. Occupations and hobbies of parents. 3. Experiences which may influence attitudes toward science such as elementary school science, high school science courses, high school science teachers, attitudes toward science requirements, high school courses liked most, high school courses liked least, and membership in science clubs. 4. College science courses completed. 5. Extent of the interviewees' present interest in science, Finally, the circumstances surrounding the tentative choice of a science career by those who once considered such a career will be discussed.
- The Adaptability and Present Status of Andropogon Ischaemum L. in Denton County, Texas
- This investigation has been made with reference to the adaptability of Andropogon ischaemum, King Ranch bluestem, to various soils, various slopes, and various erosion conditions in Denton County.
- Responses of Selected Texas Fishes to Abiotic Factors, and an Evaluation of the Mechanisms Controlling Thermal Tolerance of the Sheepshead Minnow
- Low oxygen tolerances of ten fishes were estimated using an original nitrogen cascade design, and reciprocally transformed to express responses as ventilated volume necessary to satisfy minimal oxygen demand (L·mg O2^-1). Values ranged from 0.52 to 5.64 L·mg^-1 and were partitioned into three statistically distinct groups. Eight stream fishes showed moderately high tolerances reflecting metabolic adaptations associated with stream intermittency. Juvenile longear sunfish and two mollies comprised the second group. High tolerance of hypoxia may allow juvenile sunfish to avoid predation, and mollies to survive harsh environmental oxygen regimens. The sheepshead minnow was the most tolerant species of low oxygen, of those examined, explaining its presence in severely hypoxic environments.
- Production and Energy Metabolism in Three Benthic Insect Populations in a Small North Central Texas Pond
- Annual energy budgets of dominant benthic macro-invertebrates were examined during November 1973 to October 1974 from the benthos of a small pond ecosystem in north-central Texas. Estimates of annual secondary production (Hynes and Coleman 1968) were Procladius s. (Diptera, Chironimidae), 2.4 g m^-2 y^-1 (13 kcal m^-2 y^-1 ); Tendipes decorus (Diptera, Chironomidae), 6.0 g m^-2 y^-1 (40 kcal m^-2 y^-1 ); Brachycercus sp. (Ephemeroptera, Caenidae), 1.9 g m^-2 y^-1 (11 kcal m^-2 y^-1). Energy metabolism was measured in the laboratory at six seasonally encountered temperatures (5, 10, 15, 20, 25, and 30 C) on an acclimatization basis, and then extrapolated to the field. Estimates of annual energy metabolism are Procladius sp., 5.0 kcal m^-2 y^-1 ; Tendipes decorus, 17.2 kcal m^-2 y^-1 ; Brachycercus sp. 40.0 kcal m^-2 y^-1.
- Documentation of Biodiversity Impacts (Including Cumulative Biodiversity Impacts) in Environmental Impact Statements
- In the United States, biodiversity impact assessment has historically received little attention. Responding in 1993, the Council on Environmental Quality (CEQ) released guidelines on incorporating biodiversity into environmental impact assessment under the National Environmental Policy Act of 1969. The objectives of the study here were to identify the level of documentation of biodiversity impact assessment in sample Environmental Impact Statements (EISs); identify whether in the years following the release of 1993 CEQ guidelines any significant changes have taken place in assessment of biodiversity; identify deficiencies, and if the need exists, formulate appropriate recommendations and approaches for addressing biodiversity in EISs. The study involved a systematic review of 30 EISs published since the release of CEQ guidelines, and five EISs published prior to it. The review involved answering a series of standard questions, which attempted to ascertain the level of biodiversity impacts included in each impact statement. Trends in approaches to biodiversity impact assessment were investigated and deficiencies summarized. The analysis resulted in a series of recommendations for improving the manner in which biodiversity impact assessment can be approached.
- Assessment of Changes in Aquatic Macrophyte Occurrence Following Introduction of Triploid Grass Carp in a North Texas Reservoir
- The objectives of this project were to measure changes in frequency of occurrence of submerged macrophytes over the first two growing seasons following stocking with triploid grass carp at two fish per acre and to measure differences in macrophyte biomass between areas excluded from herbivory and adjacent control sites after 16 months following establishment of exclosures. The project also seeks to measure concentrations of fluridone following the herbicide treatment, and to compare two methods of aquatic vegetation sampling.
- Parasites of the Cricket Frog, Acris Crepitans, of Denton County, Texas
- The purpose of this study was threefold. The literature concerning parasites of A. crepitans was to be brought up to date. Contributions to the general body of knowledge pertaining to the parasitic fauna of host specimens of A. crepitans and specifically those found in Denton County, Texas, were to be made. Finally, specimens found parasitizing host specimens of A. crepitans were to be preserved and classified.
- Genetic Differentiation of the Geomys Pocket Gopher Complex of Texas
- Genetic variation was analyzed for populations of seven taxa comprising four cytotypes of the Geomys bursarius chromosome complex, including G. b. major, G. b. knoxjonesi, and the Edwards Plateau taxa, G. b. llanensis and G. b. texensis. Genetic relationships of the Edwards Plateau gophers with other taxa and between themselves were examined. Genetic similarity, number of fixed allelic differences, and ectoparasite distribution indicate the Edwards Plateau gophers are a distinct gene pool. Isolation of the Edwards Plateau taxa precludes contact zone analysis. However, genetic differentiation is typical of that between other species of Geomys, and the Edwards Plateau taxa should be recognized as G. texensis. Distributions of allelic frequencies indicate little justification in retaining the subspecific status of the Edwards Plateau forms.
- A Study of Selected Factors Influencing Science Majors Toward Science Careers
- "The purpose of this study is to gather information concerning some factors which may have operated to influence science majors in North Texas State College toward science careers."--4.
- A Bio-Chemical Comparative Study of the Plankton in Lake Dallas and Pecan Creek
- The purpose of this investigation is to compare the dissolved and suspended organic material in Lake Dallas to that coming into the lake through Pecan Creek.
- Sanitary Aspects of Milk and Dairy Products Dispensed in Sherman, Texas
- The aim of this investigation is to determine whether there is a correlation between the sanitary condition of milk and dairy products dispensed in Sherman, Texas, and the plate counts, the morphology, and the Gram stain reaction of the organisms in predominant colonies from these.
- The Production of Fragile Cysts by an Aberrant Strain of Azotobacter Chroococcum Isolated from Soil
- The purpose of this study is to determine if a strain of Azotobacter chroococcum isolated from the soil in northern Louisiana produces cysts which are as resistant to deleterious agents as those produced by previously reported strains os Azotobacter.
- Geographic Variation in Chromosomes and Morphology of Peromyscus Maniculatus in Texas and Oklahoma
- This study was initiated after finding two chromosomal types of Peromyscus maniculatus north and south of the Red River in Texas and Oklahoma. The problem was to explain the chromosomal variations and their implications to the systematics of the grassland subspecies of P. maniculatus in this region.
- Presence of Krebs Cycle Intermediates in Primary Mycelia of an Actinomycete
- The purpose of this study is to determine the presence or absence of a typical Krebs cycle metabolism in the primary mycelia of an aquatic streptomycete.
- Use of Remote Sensing for Cover Type Interpretation Over the Ray Roberts Reservoir Area
- As part of a pre-impoundment study for the Ray Roberts Reservoir Area, Landsat-5 multi-spectral scanner (MSS) imagery was used for cover type interpretation. This research was concerned with analysis techniques for MSS images and a comparison of results obtained using computer assisted interpretatin of MSS images and a comparison of results obtained using computer assisted interpretation of MSS images with those obtained using manual interpretation of false color infrared (CIR) photographs.
- Trophic Structure and Energy Flow in a Texas Pond
- Annual energy flow and mean annual biocontent of eighteen compartments were determined for a 0.94 ha north central Texas pond ecosystem. Annual primary production was 7,780 kcal m^-2 yr^-2, and community production-to-respiration ratio was 1.49. One-third of annual primary production accumulated on the substrate as silt and sedimentation. Community production, production-respiration ratio, and biocontents of all compartments except aquatic insects were large in summer, small in winter. Biocontents of four trophic levels in the pond were all of the same order of magnitude, approximately 50 kcal m^-2. Suspended and benthic organic material forprimary consumers and terrestrial insects for tertiary consumers were substantial allochthanous energy imports into the pond system.
- Rectal Temperatures of the Cotton Rat, Sigmodon Hispidus (Rodentia : Cricetidae)
- This investigation has been concerned with determining the extent to which a small mammal, the cotton rat, may become acclimated to environmental temperatures, and the influence acclimation has upon a population. The study was also designed to determine if acclimation effects on a population can be seen in individual rats.
- Development of a Watershed Prioritization Strategy Using Remote Sensing and the Geographic Resource Analysis Support System. Case study: City of Carrollton, Texas
- This study used a geographic information system (GIS) and an empirical pollutant load model to estimate average annual pollutant loads contained in storm water charges from the City of Carrollton, Texas. The Geographic Resource Analyses Support System (GRASS) was used to create a number of spatial data layers as input variables to a model that estimates loads in Kilograms/Hectare/Year, and Kilogram/Basin/Year. Average annual pollutant loads for twelve pollutants were derived from average annual rainfall/runoff volumes, coupled with Local Dallas/Fort Worth Metroplex storm water Event Mean Concentrations.
- Bacterial Survey of the Sources of Drinking Water of Trinidad, Texas, with Special Reference to Sanitation
- A bacterial analysis of the water from thirty-six sources of consumption by the white population of Trinidad, Henderson County, Texas, was made to determine the potability of each of these in regard to infection from typhoid or related organisms.
- Biology and Energetics of Tropisternus Lateralis Nimbatus (SAY) (Coleoptera: Hydrophilidae) in a Playa on the Southern High Plains of Texas and Aquatic Coleoptera Diversity from Seven Playas on the Southern High Plains of Texas
- A study of the biology of Tropisternus lateralis, a hydrophilid beetle, was conducted during the flood period of a single playa on the Southern High Plains of Texas from early June 1995 through early September 1995. Mechanism of colonization, tolerance/avoidance to drought, larval density, and secondary production were analyzed. T. lateralis colonized playas from surrounding aquatic habitats and avoided drought through aerial dispersion. Once in the playa, larval density increased over time. Secondary production was 1.31 g/m2/.25 yr. In addition, aquatic Coleoptera diversity was studied in seven playas on the Southern High Plains of Texas. A total of twenty three species were identified from the study region. Nine species not reported in playa literature were identified.
- A Quantitative and Qualitative Bacterial Analysis of Pecan Creek
- Since Pecan Creek receives sewage wastes from an obviously inadequate disposal system, it seemed possible that it could receive pathogenic bacteria. The fact that these might be present in numbers sufficient to cause epidemics, provided the proper natural vectors were present, stimulated an interest in and the pursuance of this study.
- Age, Growth, and Food Habits of the Largemouthed Black Bass (Micropterus Salmoides) and the Spotted Bass (Micropterus Puctulatus SSP) in North and East Texas Lakes
- This study is based on the examinations and analyses of 388 largemouthed black bass (Micropterus salmoides) and 118 spotted black bass (Micropterus puctulatus ssp.) which were collected over a period of three years from 9 lakes in the North-Central and East Texas areas. The results should show the following: (1) the average age of the black bass in each of the nine reservoirs in Texas; (2) the growth rate of the bass in these reservoirs; (3) the feeding habits of the bass in all reservoirs studied; (4) a comparison of the growth rates of the largemouthed and spotted basses; and (5) a comparison of the growth rates of bass from Texas and Oklahoma.
- Genic Differentiation and Evolution in the Ground Squirrel Subgenus Ictidomys (Spermophilus)
- The genetic structure of 26 natural populations of three species (S. tridecemlineatus, S. mexicanus, and S. spilosoma) of the Ictidomys subgenus of ground squirrels was analyzed using chromosomal and electrophoretic techniques. Chromosomal variation was not observed in S. mexicanus, and only slight karyotypic variation was found in the other two species. Chromosomal evidence indicated hybridization between S. tridecemlineatus and S. mexicanus, placing these species within the classical definition of semispecies. Analysis of electrophoretic variation at 29 genetic loci indicated close genetic relationships between these species. Evolution in Ictidomys appears to be linked with Pleistocene events, and speciation appears to have occurred within the last 155,000 years.
- Seasonal and Spatial Variability of the Microcrustacean Community in Lake Texoma, Texas and Oklahoma
- Twenty-eight species of zooplankton were identified from Lake Texoma. Seasonal density of the overall microcrustacean community and seasonal cycles of individual species were compared with northern populations and any available literature from the Southwest. Cycles of occurrence and abundance were similar to those observed in northern populations but tended to occur earlier in the year due to higher temperatures. Spatial distributions within the reservoir were heavily influenced by nutrient and salt input from the Red River, which resulted in dense populations in the Red River Arm. In addition, during the summer, the microcrustacean community was restricted to the epilimnion due to anoxic conditions in the hypolimnion of the reservoir.
- Studies on Microorganisms in Jet Aircraft Fuel Systems
- Laboratory and field investigations during the past ten years have demonstrated that certain microorganisms can cause deleterious effects in jet fuel tank systems. These investigations have brought about new concepts concerning the mechanisms of utilization of certain constituents in jet fuel tanks by microorganisms. Since the presence of microorganisms is inevitable in fuel systems, research efforts have been directed towards identification and determination of the types of microorganisms which can utilize jet fuel hydrocarbons, fuel additives, polyurethane foam structural materials, and particular hydrocarbons present in the fuel.
- A Correlation of Humus with Water Content and Crop Rotation in San Saba and Denton Clays, Denton County, Texas
- A study of the humus content and the water content of San Saba clay and Denton clay. Studies show that the physical properties of soil are conducive to moisture retention and the availability of moisture to plants.
- Antibacterial Effect of the Oleoresins of One Hundred Common Texas Plants upon Twenty-Five Gram-Negative Mirco-Organisms
- This investigation deals with the study of the possible antibiotic effect of oleoresins of one hundred common Texas plants upon twenty-five gram-negative bacterial organisms.
- Assimilation of Inorganic Nitrogen by Aquatic Actinomycetes
- It was the purpose of this investigation to present laboratory data concerning the assimilation of inorganic nitrogen by the aquatic actinomycetes. The strains of aquatic actinomycetes under consideration represented a cross section of those currently under culture at North Texas State University.
- Life Histories of Stoneflies (Plecoptera) and Other Aquatic Insects in the Rio Conejos Drainage, Colorado
- Stonefly life histories were studied March, 1987 through May, 1990 in the Rio Conejos, Colorado. Adult presence phenology and intensity were monitored daily in the summers of 1988 and 1989 and were coupled with monthly benthic samples to assess nymphal growth. Eggs of several species were reared. Thirty-one species were collected, with several multi-species assemblages occurring in Capnia, Utacapnia, Taenionema, Suwallia, Triznaka, Isogenoides and Isoperla. Sufficient data were obtained to reveal partial or complete life histories of 13 species, five of which have not been previously reported. New information included the 9- to 10-mo egg diapause and semivoltine life histories of Isogenoides zionensis Hanson, Pteronarcella badia (Hagen) and Pteronarcys californica Newport. Additionally, Isoperla phalerata (Smith) had univoltine-slow growth, and L quinquepunctata (Banks) was univoltine-fast. Previously unstudied emergence periods are presented for Triznaka signata (Banks), Suwallia wardi Kondratieff and Kirchner and S. pallidula (Banks). The later two species temporally segregated emergence in both years. Isoperla fulva Claassen emerged in June, and was temporally segregated from its congeners. Regression analysis of cumulative percentage catch revealed two adult presence patterns. Eight species had slopes <7%/d (extended pattern), and only two, I. zionensis and P. cal'fornica, had slopes >7 %/d (synchronous pattern). Several stoneflies were more abundant in Massey Creek, a tributary of the Rio Conejos. The emergence and diversity of mayflies, stoneflies and caddisflies was studied there. During May-August, 1989, 46 species were collected using sweepnetting and emergence traps. Chloroperlid stoneflies were abundant, with Suwallia nr. lineosa (Banks) contributing 37% of the total catch. Slopes of adult presence ranged from 1.7 %/d for Epeorus alberta (McDunnough) to 6.2%/d for Rhyacophila pellissa Ross. Separation of patterns was more difficult here, but < 4%/d was used as a criterion for extended emergers. A cluster analysis of 17 species produced three clusters that corresponded to stream …
- Plasma Ion Concentrations in Selected Fishes from Four North Central Texas Reservoirs with Different Salinities
- Mean salinity concentrations in the four reservoirs (Moss, Ray Hubbard, Texoma and Possum Kingdom) ranged from 0.2 ppt in Moss Lake to 2.01 ppt in Possum Kingdom Lake. Reservoir sodium and chloride concentrations were hypotonic to hypertonic to plasma levels in all species. Interspecific differences were seen in ionic concentrations within each reservoir. Total osmotic and sodium concentrations in carp, Cyprinus carpio, were correlated to their concentrations in the reservoirs. No such relationship was noted for chloride, potassium and calcium. A laboratory study indicated that fish collection by electroshock did not bias plasma ion concentrations. Exposures to wide variations in ionic concentrations did not appear to induce stress in the species studied.
- Herpetology of the Amistad Reservoir Area, Val Verde County, Texas
- The Amistad Reservoir in southern Val Verde County, Texas will impound a considerable amount of surface water in a semi-arid region in which natural surface water is scarce. Construction of the dam began in 1963 and the reservoir began to fill in the summer of 1968. This large impoundment could have a considerable ecological impact on the area. The purpose of this research was to study the ecological distribution and zoogeographic affinities of the herpetofauna and to establish an ecological baseline against which any future changes could be measured.
- An Investigation of Microbial Antagonism in Ten Denton County, Texas Soils
- This thesis is concerned primarily with the growth and detection of soil microorganisms in ten Denton County, Texas, soils antagonistic to a specific gram-positive and a specific gram-negative bacterial organism.
- The Effects of Hexadecanol on the Microbiota of Lake Hefner
- It seemed desirable to investigate more fully the effect of hexadecanol on the microbial population of a reservoir. It was the purpose of this investigation to determine the effect of hexadecanol on the micro-biota of Lake Hefner, to ascertain which organisms were stimulated by hexadecanol both in the laboratory and the reservoir, and to investigate the degradation of hexadecanol by microorganisms selected from Lake Hefner.
- The Chemical Compounds Produced by Actinomycetes and Their Relation to Tastes and Odors in a Water Supply
- The purpose of this problem was to determine the cause of tastes and odors in the Breckenridge water supply and to isolate and culture the organisms responsible for the offensive chemicals.
- Survival and Growth of Bacteria in Chlorine Treated Water
- In this problem, an attempt was made to determine the fate of various species of bacteria which had previously been isolated from other sources when inoculated into Denton tap water.
- A Grassland Evaluation of Eastland County, Texas
- This investigation has had for its purpose the determination of first, all members of the Gramineae (Grass) family found in the county; second, the incidence of each species with the various types of soil; third, the grazing value of each species; fourth, the life span of the parent plants; fifth, the present grassland status; and sixth, the potentialities of developing desirable grassland.
- Density, Distribution, Production and Drift of Benthic Fauna in a Reservoir Receiving Thermal Discharges from a Steam Electric Generating Plant
- The effects of thermal discharges on the density, distribution, production, and drift of benthic organisms were studied at North Lake reservoir.