is in evident harmony with their habits. For, as with other female birds, one 

 of the most critical periods of their lives is the time of brooding, when, hour 

 after hour and day after day, they have to sit on top of their open nests, in 

 quiet, steady-lighted nooks. Even when, as is usually the case, the females 

 as well as the males feed in the gay, sunlit upper border of the forest, they 

 descend into the shady underworld to nest. Hence the fitness of their being 

 softly colored and delicately counter shaded, while their mates are adorned 

 with magnificent jewel-spots and strange appendages. In this matter hum- 

 mingbirds will serve to exemplify the whole group of forest birds in which 

 the sexes are decidedly unlike. The female, almost without exception, is 

 colored and shaded in the way which best conceals her while she is brooding; 

 whereas the male is colored for active life among the leaves and flowers. 

 Corresponding sexual differences of habits and plumage occur among other 

 than woodland birds. Those of ducks I have already mentioned. 



io6 



