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.

This investigation was concerned with the relationship of the slime layer material of Pseudomonas aeruginosa, Verder and Evans strain 1369, to the presumably somatic "O" type of antigen used by these authors as the base for their serological schema.

The present study was on the isolation of a bacterium capable of producing filtrable forms which passed through the 0.45µ filter membrane and regenerated the parental form; the testing of the true filtrability of the isolate; the relationship between growth of the isolate and appearance of filtrability; partial characterization of the isolate and visualization of the elements that passed through the membrane filter with electron microscopy and shadow casting technique.

The purpose of this research was to attempt to duplicate the in vitro bactericidal test against Pseudomonas aeruginosa as reported by Bjornson and Michael and to correlate agglutinating titer of an antiserum to protective activity.

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.

The respiratory activity of three aquatic animals selected from different pollution index classifications is examined in the presence of sublethal concentrations of Dibrom, a commonly used, broad-spectrum, organophosphate insecticide.

In this study, branchiobdellids were collected from crayfish captured from two adjacent sites in Denton County, Texas. Identification of the branchiobdellid, Cambarincola vitrea Ellis, was first made and then work was extended to include several topics of ecological interest.

The purpose of the investigation was to locate the plant population which had the greatest impact on soil nitrogen in a successional sequence from newly deposited alluvia to a mature streamside forest, and to evaluate the pioneer populations in terms of their annual nitrogen contribution.

Two isoenzymes of malate dehydrogenase were isolated and partially purified from the midge larva Glyptotendipes barbipes. Differential centrifugation followed by cellulose acetate and polyacrylamide gel electrophoresis revealed one isoenzyme associated with the mitochondrial fraction and another form found only in the cytoplasm.

The purpose of this investigation is to determine the effect of varying geosmin concentrations on the growth of selected cyanophytes which did not produce a notable odor in culture.

A large, multi-basin, reservoir (Garza-Little Elm Reservoir) in north central Texas was studied to determine the relative effects of various parameters on primary productivity. The basins were impounded several years apart,thus allowing the influence of age on water chemistry and biota to be considered. Another principal influence on water quality was secondary sewage effluent that entered one basin from a nearby source.

The effects of light, light "mimicking" chemicals, and protein synthesis inhibitors on the photo-induced carotenogenesis of Corynebacterium 7EIC were studied. Changes in the dosage of fluorescent light applied to dark grown cells showed a dose related carotenogenic response. Maintaining the same dosage but varying the wavelength of monochromatic light revealed that light with a wavelength of 280 to 450nm was responsible for photo-induction. It further showed a peak of photo-induction between the wavelengths of 370 and 430nm. The light "mimicking" chemicals antimycin A and p-Chloromercurybenzoate were shown to have no light "mimicking" effects. The transcriptional inhibitor of protein synthesis actinomycin D partially inhibited, and chloramphenicol a translational inhibitor, completely inhibited photo-induced carotenogenesis.

In view of the discrepancies and conflicts produced by previous studies on amphibian lymph hearts, a study was initiated to reinvestigate the pharmacological, temperature, and electrical aspects of lymph heart physiology. Bullfrogs were chosen as the experimental animal, All lymph heart responses to experimentation were physiographically recorded as myograms and electrograms. The results are in agreement with previous studies on some aspects and in conflict on others. From the results obtained, lymph heart muscle appears to possess both skeletal and cardiac muscle properties as evidenced by drug responses and reactions to temperature. The precise components of the electrogram remain unclear. It is suggested that further investigation should be made to better determine the true nature of lymph hearts.