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vi, 152 leaves, appendix : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1973) from the dept. of Zoology, University of Adelaide

163 leaves : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Zoology, 1970

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 5 uppsatser.

Diss. (sammanfattning) Uppsala : Univ., 2001. / Härtill 4 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.

Diss. (sammanfattning) Stockholm : Karol. inst., 2001. / Härtill 6 uppsatser.

A method is described for the preparation of an everted rectal sac of the desert locust. Water and solute absorption by the rectum was determined by measuring changes in hemocoel fluid and rectal tissue. Initial absorption rates of Na, K, Cl, water and trans-rectal potential are comparable to those in vivo under similar conditions. After an initial transient period (1 hour), transport activity of the in vitro rectum remained in a steady state for at least 4- hours. The relationship between osmotic gradient and steady state rate of net water movement across the rectal wall was determined. Absorption of water is partially inhibited by anoxia, malonate (10־² M), dinitrophenol (10־³M), potassium cyanide (10־³ M) plus iodoacetate (10־³ M) and ouabain (10־³ M). Tissue ions and water are secreted into the hemocoel compartment when the rectal sac is incubated in isosmotic pure sucrose solution. Dependence of water movement on solute transport is indicated by the requirement of lumen ions for prolonged maintenance of water absorption. Effects of different ions (Na, K and Cl) in bathing media on absorption rate of water and ions, absorbate concentrations, trans-epithelial electro-potential differences, and tissue compositions were determined. Observed properties of water and solute movement in vitro are discussed and evaluated in relation to possible mechanisms for active absorption of water. Possible locations of transport sites are suggested in a hypothetical scheme based on the ultrastructure of rectal epithelium. / Science, Faculty of / Zoology, Department of / Graduate

published_or_final_version / Zoology / Doctoral / Doctor of Philosophy

Water consumption, and weight loss in response to water deprivation and saline water consumption, were studied in the Eutamias townsendii townsendii from Portland, Multnomah County, Oregon. These chipmunks occupy moist Pacific Northwest forests. The results of these studies suggest that Townsend's chipmunks are dependent on sources of drinking water, at least for normal above ground activity, that their tolerance for water deprivation is comparatively low, and that they are unable to obtain a net gain of water by drinking 0.2 M sodium chloride solutions. Chipmunks cannot drink 0.4 M NaCl solution and survive for more than a few days. Metabolic water and preformed water in air dry food are not adequate to meet these animals' water needs.