284 



GERM-CELL CYCLE IN ANIMALS 



the male germ-cell cycle, especially in mammals, 

 mollusks, and insects, and appear to be continuous 

 from one generation of cells to the next. During 



Fig. 79. — Behavior of the mitochondria during the fertilization and 

 early cleavage of the egg of Ascaris. A. Egg into which a sperma- 

 tozoon has penetrated. B, C. The mixing of the mitochondria of 

 the egg and spermatozoon. D. Division stage of the first two blas- 

 tomeres. (After Aleves, 1911 and 1914.) 



mitosis the plastosomes lie outside of the spindle 

 (Fig. 79, D) ; they may divide autonomously as 

 claimed by Faure-Fremiet (1910) in Protozoa (Fig. 



