. The effects of inanition and malnutrition upon growth and structure. Starvation; Nutrition. -Testis 9. nsr Fig. 7, a to d.—To illustrate the changes in size and external form of the fresh-water polyp. Hydra fusca, during starvation. All Xio. (After Schultz '06.) a, Normal Hydra; b, Hydra starved 1J-2 weeks; size reduced, but form still nearly normal; c, later stage of reduction; tentacles have become rudimentary; the testis has matured, in spite of the atrophy of the body as a whole; d, terminal stage of reduction (cf. Figs. 8-11). Nussbaum ('87, '93) was the first to study the effect of ina
. The effects of inanition and malnutrition upon growth and structure. Starvation; Nutrition. -Testis 9. nsr Fig. 7, a to d.—To illustrate the changes in size and external form of the fresh-water polyp. Hydra fusca, during starvation. All Xio. (After Schultz '06.) a, Normal Hydra; b, Hydra starved 1J-2 weeks; size reduced, but form still nearly normal; c, later stage of reduction; tentacles have become rudimentary; the testis has matured, in spite of the atrophy of the body as a whole; d, terminal stage of reduction (cf. Figs. 8-11). Nussbaum ('87, '93) was the first to study the effect of inanition upon sexual development in Hydra. He concluded that the (normally hermaphroditic) Hydra when abundantly fed will produce ovaries only; when moderately fed, both ovaries and testes; while those scantily fed produce testes only. This question is of fundamental importance in the theory of sex-determination, and has occasioned much controversy. Hertwig ('06) opposed Nussbaum's view, and maintained that the condi- tions for sexual differentiation in Hydra are more complicated, temperature being a more important factor than nutrition. In his colony, sex-organs (always male) appeared only at lower temperature, whether starved or well-fed. The testes were better developed in the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Jackson, Clarence Martin, b. 1875. Philadelphia, P. Blakiston's son & co
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