The Recognition of Sex 235 



excitement and aggressiveness. And the two males 

 are sure to fight if they can reach one another. 



"But if the strange bird is a female, she acts far 

 otherwise. She is at first very indifferent, unless she 

 is particularly anxious to mate. And after some 

 days, when she begins to show an interest in the 

 male, she does not give the bowing-coo, nor charge 

 up and down the cage, nor show other signs of pug- 

 nacity and aggressiveness. So far from tending, to 

 aggress the male, her conduct is rather an expres- 

 sion of submission to him. She shows a certain 

 excitement; for instance when she utters the kah it 

 is a kah expressive of gentle excitement. But she 

 spends the greater part of her time in alluring the 

 male by means of the nest-calling performance — the 

 nest-calling attitude, seductive cooing, and gentle flip 

 of the wings. She often tries to get through the 

 bars of her cage to the male; and, failing to do so, 

 she sometimes lies down with one side pressed against 

 the bars. . . . 



"When the male sees the strange bird behaving 

 in this submissive and seductive manner, he loses 

 the intensity of his pugnacity ; though he always con- 

 tinues to be masterful. He spends less time now 

 in the bowing-coo and more time in nest-calling and 

 in trying to get to the female." 



In the mammals the sense of smell plays a much 

 larger part in the recognition of sex than it does 

 in birds and the lower vertebrates. Not only is 

 the sense of smell as a rule acute, but scent glands 



