The Survival of the Fittest 



The moUusks are surviving abundantly, but 

 have made very little progress. Crustacea, or 

 some ancestor of the Crustacea, have given birth 

 to insects. But these small, short-lived forms, 

 governed by instinct, are no match for their 

 larger competitors, which have started along the 

 road which leads to warm blood, long life, and 

 Intelligence. These latter are all descendants of 

 the poor primitive vertebrate which seemed al- 

 ready distanced In the race at the beginning of 

 paleozoic time. 



In the jungles, where food Is most abundant, 

 we see reptiles of every form and kind. Some 

 stalk on two legs; others walk or run on four, 

 much like our present herbivorous cattle. 

 Others wade or swim in the great lakes. Some 

 fly with batlike wings. In the sea great lizards 

 flourish. Many of these are large and powerful, 

 some of them swift and agile. They have heavy 

 jaws and strong teeth. Many or most are mail- 

 clad. No other form can join battle with them. 

 Birds are flying through the air, though still per- 

 haps half reptilian In form and appearance. We 

 find a few small mammals, no one of them a 

 match for even the weaker reptiles. 



Once more, which is the fittest? We must 



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