lO 



3. The Advance of Embryology. 



The egg a cell, Sch\vaNx\ (1838). 



Cell-lineage traced to the egg, Reichert (1840), 

 KoLLiKER, and Virchow. 



Function of spermatozoa, experiments of Kolliker 

 and Reichert. 



The spermatozoon a cell, K lliker, La Vallette, 

 and Flemmix(;. 



Fusion of the nuclei in fertilization, Oscar Hertwig 



The same process in plants, Strasijurger (1884); 

 GuiGNARD (1 89 1). (See Amer. Nat., 1892, p. 424.) 



4. Modern Theories of Fkktilizatiox. 



Two-fold effect of fertilization. 



Parthenogenesis. 



Normal and parthenogenetic eggs compared. 



Weismann's Theory. 



MiNOT (Embryology, p. yy). 



Geddes and Thomson (Evolution of Sex, p. 183). 



Composition of male and female nuclei. 



AuERBACH ( 1 89 1 ). (See Amer. Nat., 1 892, p. 624.) 

 Watase' (Jour. Morph. Vol. 6, p. 482). 



The bearer of heredity ? 



Theories of Hertwhv, Weismann. 



BovARi's experiments (Amer. Nat., Vol. 27, p. 222). 



Seeliger's criticism (Jour. Royal Mic. Soc, 1895, 



p. 318). See also Amer. Nat., Vol. 29, p. 286. 

 Observations of Fol, Guignard, and Conklin. 



(Woods Holl Lectures 1893, p. 15). 



