THE MECHANISM OF EEPEODUCTION 39 



somes characteristic of the body cells (Fig 10). and since 

 it is a matter of chance what gametes unite, such gametic 

 differences as we have illustrated would give a possibility 

 of obtaining 8 x 8 or 64 types of zygotes. 



Fig. 10. — Diagram to illustrate fertilization; cT, male pronucleus; 9 , female pro- 

 nucleus; observe that the chromosomes of maternal and paternal origin, respectively, do 

 not fuse. (After Guyer.) 



The mechanism of the process of gametogenesis and 

 fertilization in animals need not concern us further here. 

 We must speak of the process in the seed plants, however, 

 for a rather odd phenomenon occurs there to which there 

 will be occasion to refer later. 



