THE FERTILIZED EGG-CELL. 



175 



to the female egg-cell, penetrates the membrane of the latter 

 by a perforating motion and coalesces with its cell-material. 



Fig. 18. — -Fertilization of the egg- 

 cell by the sperm-cells. The thread- 

 shaped, lively sperm. cells penetrate 

 through the porous canals of the egg- 

 membrane into the granular mass of 

 yelk, with which they amalgamate. 

 The kernel (nucleus) of the egg-cell 

 has disappeared. 



A poet might find in this 

 circumstance a capital oppor- 

 tunity for painting in glowing 

 colours the wonderful mystery of the process of fertiliza- 

 tion ; he might describe the struggles of the living " seed- 

 animalcules " eagerly dancing round the egg-cell shut up 

 in its many coverings, disputing the passage through the 

 minute pore-canals of the chorion, and then " of purpose " 

 burying themselves in the protoplasm of the yelk-mass, 

 where, in a spirit of self-sacrifice, they completely efiace 

 themselves in the better " ego." Or a teleologist might 

 here find occasion to admire the peculiar wisdom of the 

 Creator, who made many fine pore-canals in the egg- 

 membrane in order that the seed-animalcules might pass 

 through them. But the critical naturalist very prosaically 

 conceives this poetical incident, this " crown of love," as the 

 mere coalescence of two cells. The result of this is that, in 

 the first place, the egg-cell is rendered capable of further 

 evolution ; and, secondly, that the hereditary qualities of 

 both parents are transmitted to the child. 



The fertilized egg-cell is, therefore, of a nature entirely 

 different from that of the unfertilized egg-cell. For since 



