6 PECKHAM. [Vol. 1. 



the nature of the pigment in their feathers, it would be prema- 

 ture to discuss it in this connection. 



Let us see how far the hypothesis that brilhant coloring is 

 correlated with high vitality is supported by facts. Wallace 

 makes the activity and pugnacity of an animal the criterion of 

 its vitality ; and where the male bird takes charge of the eggs and 

 incubates them, he considers this change of habit, along with 

 the pugnacity of the female, a proof that in such cases she pos- 

 sesses the higher vital energy, pugnacity being the important 

 factor. " Of the mode of action of the general principles of 

 color-development among animals," ^ he says, " we have an 

 excellent example in humming-birds. * * * The more 

 vivid colors, and more developed plumage of the males, I am 

 now inclined to think may be wholly due to their greater vital 

 energy, and to those general laws which lead to such superior 

 developments even in domestic breeds; but in some cases the 

 need of protection by the female while incubating, to which I 

 formerly imputed the whole phenomenon, may have sup- 

 pressed a portion of the ornament which she would otherwise 

 have attained." In view of the importance of this point the 

 following evidence, offered in its support, seems rather meagre. 

 " The extreme pugnacity of humming-birds has been noticed 

 by all observers, and it seems to be to some extent proportioned 

 to tlie degree of colour and ornamentation in the species. Thus 

 Mr. Salvin observes of Eugenes fulgens, that it is 'a most pug- 

 nacious bird,' and that ' hardly any species shows itself more 

 brilliantly on the wing.' Again, of Campy lopterm hemileu- 

 curus, — 'the pugnacity of this species is remarkable. It isvei'y 

 seldom that two males meet without an aarial battle,' — and ' the 

 large and showy tail of this humming-bird makes it one of the 

 most conspicuous on the wing.' Again, the elegant frill-necked 

 Lophornis ornaius ' is very pugnacious, erecting its crest, throw- 

 ing out its whiskers and attacking every humming-bird that 

 may pass within its range of vision;'' and of another species L. 

 magnificus, it is said that ' it is so bold that the sight of man 



1 The italics .ire ours. 



