53O WM. A. KEENER AND J. B. LOOPER. 



The first phase has reference to the nutrition of an oogonium 

 of the final generation. This oogonium is nourished through 

 the disintegration and resorption of adjacent interstitial cells. 

 Through the nourishment, thus obtained, the final oogonium 

 grows into a large pseudopodial cell, the primary oocyte. The 

 first nutritional phase is referred to the growth of the final 

 oogonium into a primary oocyte. It does not involve yolk- 

 formation. 



The second phase of nutrition begins with the primary oocyte 

 lying, as a pseudopodial cell, in extended relation to the endoderm. 

 Yolk is elaborated by the oocyte from material handed over by 

 the endoderm and the protoplasm of interstitial cells is not 

 involved. The second nutritional phase is referred to the de- 

 velopment of the zygote. 



LITERATURE. 

 Brauer, A. 



'91 Ueber die Entwicklung von Hydra. Zeit. f. Wiss. Zool., Bd. 52, 2. 

 Downing, Elliot R. 



"08 Ovogenesis of Hydra Fusca. BIOL. BULL., Vol. 15. 

 Fewkes, J. W., and E. L. Mark. 



'84 Embryological Monographs, III. Acelephs and Polyps. Memoirs of the 

 Mus. Comp. Zool., Vol. IX., No. 3, Harvard College, Cambridge, Mass. 

 Kepner, Wm. A., and D. L. Hopkins. 



'24 Reactions of Hydra to Chloretone. Journ. Exp. Zool., Vol. 38. 

 Kleinenberg, N. 



'72 Eine anatomisch-entwicklungsgeschichtliche Untersuchung. Leipsig. 

 Tannreuther, G. W. 



"08 The Development of Hydra. BIOL. BULL., Vol. 14. 



