Gene Action 



303 



Egg Nucleus 

 Centrosome 



Cytoplasm 



Fig. 84. Early stages in the development of the egg of the mollusk, 

 Crepidula plana. The male and female halves of each nucleus are indicated'. 

 (Courtesy of Dr. E. G. Conklin. b-f from Heredity and Environment with 

 permission of the Princeton University Press.) 



