38 



TEXT-BOOK OF EMBRYOLOGY. 



ozoon must enter, this being of the nature of a channel through the membrane 

 —the micropyle. In some instances a little cone-shaped projection from the 



Fig. 23. — Fertilization of the ovum of Thalassema. Griffin. 

 J , Male pronucleus, /-, female pronucleus. 



surface of the egg, the attraction cone (Fig. 22, 1), either precedes or imme- 

 diately follows the attachment of the spermatozoon to the egg. Instead of a 

 projection there may be a depression at the point of entrance. 



