Copies of author's previously published articles inserted. Bibliography: p. 199-254. In eutherian mammals, the size of the testes and number of spermatozoa produced and stored in the excurrent ducts vary widely between species, with the hydromyine rodents of Australia exhibiting a greater range of interspecific variation than any other closely related group of species. This study compared the efficiency of germ cell production and sperm storage capacity in the extra-testicular ducts of two arid zone species, the plains rat, Pseudomys australis, and the spinifex hopping mouse, Notomys alexis, that have vast differences in testes size and number of stored spermatozoa. Results are discussed.

Copies of author's previously published articles inserted. / Bibliography: p. 199-254. / xii, 254 p., [34] leaves, [30] leaves of plates : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / In eutherian mammals, the size of the testes and number of spermatozoa produced and stored in the excurrent ducts vary widely between species, with the hydromyine rodents of Australia exhibiting a greater range of interspecific variation than any other closely related group of species. This study compared the efficiency of germ cell production and sperm storage capacity in the extra-testicular ducts of two arid zone species, the plains rat, Pseudomys australis, and the spinifex hopping mouse, Notomys alexis, that have vast differences in testes size and number of stored spermatozoa. Results are discussed. / Thesis (Ph.D.)--University of Adelaide, Dept. of Anatomical Science, 2000