254 ANNALS OF BIRD LIFE. 



-coloured ; in many all the outer margins of the 

 flight feathers are edged with brilliant tints, even 

 in the young, as is the case with the Goldfinch. 

 The tail has been equally modified. There are 

 species among almost every great group of birds 

 in which the tail feathers are barred or marked in 

 certain well-defined patterns. In a great many 

 cases the bars are replaced by tips of a different 

 colour from the remainder of the feathers ; whilst 

 in other cases these bars are broken up into well- 

 defined spots, which extend across the entire tail. 



As yet we are utterly in the dark respecting 

 this singular coincidence in the pattern of colour 

 on the plumage of so many widely different 

 species. It would seem as if the various internal 

 organs of birds were emphasized in many cases on 

 their dermal covering ; and that for some reason, 

 which still remains to be discovered, certain parts 

 of the body are more likely to produce these 

 colour patterns than others. The head, the back, 

 the throat, the breast, the belly, the vent, the 

 wings, and the tail have each and all been marked 

 on the plumage in a variety of brilliant or striking 

 colours. It seems as if these portions of the 

 plumage were singularly sensitive to the develop- 

 ment of such colours, perhaps aided by Sexual 

 Selection and Isolation. 



A word now as to the texture of plumage. 

 This, like everything else in nature, is wonder- 

 fully adapted to the habits and requirements of 

 the birds possessing it. Owls are birds of singu- 



