TROPICAL NATURE 



away with the rapidity of a flash of light. Such active 

 creatures would not be an easy prey to any rapacious bird ; 

 and if one at length was captured, the morsel obtained would 

 hardly repay the labour. We may be sure, therefore, that 

 they are practically unmolested. The immense variety they 

 exhibit in structure, plumage, and colour, indicates a high 

 antiquity for the race; while their general abundance in 

 individuals shows that they are a dominant group, well 

 adapted to all the conditions of their existence. Here we 

 find everything necessary for the development of accessory 

 plumes and colour. The surplus vital energy shown in their 

 combats and excessive activity has expended itself in ever- 

 increasing developments of plumage, and greater and greater 

 intensity of colour, regulated only by the need for specific 

 identification which would be especially required in such 

 small and mobile creatures. Thus may be explained those 

 remarkable differences of colour between closely-allied species, 

 one having a crest like the topaz, while in another it resembles 

 the sapphire. The more vivid colours and more developed 

 plumage of the males, I am now inclined to think, may be 

 almost 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 suppressed a portion of the 

 ornament which she would otherwise have attained. 



The extreme pugnacity of humming-birds has been noticed 

 by all observers, and it seems to be to some extent propor- 

 tioned to the degree of colour and ornament in the species. 

 Thus Mr. Salvin observes of Eugenes fulgens, that it is " a most 

 pugnacious bird," and that " hardly any species shows itself 

 more brilliantly on the wing." Again of Campy lop terus 

 hemileucurus : " the pugnacity of this species is remarkable. 

 It is very seldom that two males meet without an aerial 

 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 ornatus " is very pug- 

 nacious, erecting its crest, throwing 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 



