1 2 Introduction 



the colors of the female and the mode of nidification. That is, according to 

 Wallace, "when both sexes are of strikingly gay and conspicuous colors, the nest 

 is such as to conceal the sitting bird, while, whenever there is a striking contrast 

 of colors, the male being gay and conspicuous and the female dull and obscure, 

 the nest is open and 'the sitting bird exposed to view." This condition un- 

 doubtedly prevails in many cases, but the exceptions are so numerous and so 

 important, that the "theory" fails of adequacy. 



