434 



EVOLUTION AND ANIMAL LIFE 



two weeks old this fear was very manifest. Young mocking 

 birds will go into spasms at the sight of an owl or a cat, while 

 they pay little attention to a dog or a hen. Monkeys that have 



* 



v 



FIG. 268. Section of bark of the live-oak tree, with acorns placed on it by the California 

 woodpecker, Melanerpes formicivorus bairdii. (From photograph taken at Stanford 

 University, California.) 



never seen a snake show almost hysterical fear at first sight of 

 one, and the same kind of feeling is common to most men. A 

 monkey was allowed to open a paper bag which contained a 



