LEAF AND TENDRIL 



time governing him. In the Zoo at the Bronx the 

 peacock has been seen to strut before a crow. 



Undoubtedly the males in whom the masculine 

 principle is the strongest and most masterful are 

 most acceptable to the females, and the marvelous 

 development of fonn and color in the peacock, or 

 in the Argus pheasant, might take place under the 

 stimulus of continued success. If there are two 

 rival cocks in the yard, the hens will, as a rule, pre- 

 fer the victor — the one that struts the most and 

 crows the loudest. How amusing to see the de- 

 feated cock fold his wings, depress his plumage, 

 and look as unpretentious and henlike as possible 

 in the presence of his master! 



If the male bird sang only while courting the 

 female, we might think he sang only to excite her 

 admiration, but he continues to sing until the young 

 appear, and, fitfully, long after that, his bright col- 

 ors in many cases gradually disappearing with his 

 declining song impulse, and both fading out as the 

 sexual instinct has run its course. It was the sexual 

 impulse that called them into being, and they de- 

 cline as it declines. It is this impulse that makes 

 all male birds so pugnacious during the breeding 

 season. Not only does a brighter iris come upon the 

 burnished dove in the spring, but also a warmer 

 glow comes upon the robin's breast, and the hues 

 of all other male birds are more or less deepened 

 and intensified at this time. Among many kinds of 

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