294 CARL R. MOORE. 



6. If eggs are sectioned, after insemination subsequent to an 

 exposure to the weaker hypertonic solution, a gradient of activity 

 of spermatozoa parallels, to a certain extent, the length of the 

 exposure to hypertonic sea-water. 



7. If eggs are sectioned after insemination, subsequent to an 

 exposure to the stronger hypertonic solution, large numbers of 

 eggs are seen to have several spermatozoa within their boun- 

 daries; but they usually do not exhibit any signs of activity; 

 many are undergoing degeneration. 



8. Sperm, in gaining extrance to an egg, are pulled out into a 

 long thin chromatin band situated in the protoplasmic cone 

 produced by the protoplasm of the egg. 



9. If a pure culture of the first two cells, produced by cleavage, 

 are inseminated, sperm enter, remain entirely quiescent, and 

 may even undergo disintegration. They do not fertilize the 

 blastomeres. 



10. These experiments furnish no evidence for, but are con- 

 trary to, any view that a spermatozoon carries a substance into 

 the egg that is necessary for development. There is no evidence 

 of a sperm-borne "lysin-like" substance nor a secondary "cor- 

 rective agent." The egg possesses all the essentials for develop- 

 ment. 



HULL ZOOLOGICAL LABORATORIES, 

 March 28, 1917. 



VII. LITERATURE CITED. 



Allyn, Harriet M. 



'12 The Initiation of Development in Chsetopterus. BIOL. BULL., Vol. 24, 



pp. 22-72. 

 Blount, Mary. 



'07 The Early Development of the Pigeon's Egg with Especial Reference to 

 the Supernumerary Sperm-Nuclei, the Periblast and the Germ-wall. BIOL. 

 BULL., Vol. 13, p. 231. 

 Delage, Yves. 

 '99 Etudes sur la Merogone. Archiv. de Zoologie Exper. et Gen., 3d Ser., 



Tome 7. 



'01 Etudes Experimentales sur la Maturation Cytoplasmique et sur la Par- 

 thenogenese artificielle chez les Echinodermes. Archiv. de Zool. Exper. 

 et Gen., Ser. 3, T. 9. 

 Goldfarb, A. J. 



'16 Abstracts from American Society of Zoologists, New York City. 

 Kindle, E. 



'10 A Cytological Study of Artificial Parthenogenesis in Stronglyocentrotus 

 purpuratus. Archiv. f. Entw. Mech. d. Organismen, Bd. 31, pp. 145-163. 



