U4 



THE NEXT GENERATION 



the whale or the elephant, and no less than two cells for either 



the mouse or the mosquito. 



In this connection remember that never in the life of any 



animal do cells multiply so fast as before the creature is born. 



And this applies equally well to viviparous and to oviparous 



animals. But after 

 birth, what a differ- 

 ence ! Compare, for 

 example, the chick 

 and the rabbit. The 

 former is spry from 

 the start. He has 

 keen, round eyes. He 

 spies food at once, 

 seizes it, feeds him- 

 self, and scurries 

 about on sturdy little 

 legs, apparently hav- 

 ing a mind of his 

 own from the first. 

 Fluffy down covers 

 his body, and in sum- 

 mer, when chicks are 

 young, the warmth of 

 a sheltering mother 

 often seems alto- 

 gether superfluous. 

 It is otherwise with the viviparous small rabbit. He 



arrives in the world blind, almost naked of hair, unable to 



move in this direction or that, unable to hunt for food, able 



indeed to do nothing more than take food from his mother 



according as he needs it. 



Four Tadpoles of the European Frog 

 (Rana fusca) 



The four animals are all of the same age (three days) . 



They were raised from the same batch of eggs but 



have been kept at different temperatures. (After 



Oskar Hertwig) 



