198 THE MEANING OF EVOLUTION 



of the nucleus of the cell and carrying the determi- 

 nants which were to decide one-half of its future char- 

 acters, penetrated this egg and fused with its nucleus. 

 This was filled with the determinants of the charac- 

 ters inherited from the mother. Of course many of 

 the eggs, of which probably there are a thousand, 

 must have escaped fertilization. There are doubtless 

 a thousand sperm cells that went to utter waste for 

 one which found an egg to fertilize. These eggs 

 nestled in the crevices between the stones in the warm 

 water of the edge of the lake. Here the sun could 

 easily penetrate to the bottom and hatch them. The 

 little fish, still guarded by one hovering parent, swam 

 around in the water long before the yolk of the egg, 

 containing its large amount of food, had been ab- 

 sorbed into the tissues of the young fish. This fatty 

 store made the abdomen of the fish in which it lay 

 protrude enormously. Gradually the fish grew larger 

 and the yolk grew smaller until all had been consumed. 

 Soon the fish began to forage for himself and no 

 longer to demand or care for the company and pro- 

 tection of its parent. The little sunfish is highly 

 favored among his comrades in having any care what- 

 ever by the parent. In the case of most fishes the 

 female, swimming slowly over the bottom, deposits 

 her eggs, which are fertilized by the male, which 

 follows behind her. After the eggs have thus been 



