4.96 The Descent of Man. Part 1L 



preclude their appreciating slight changes, any more than it 

 does in the case of man. Hence with respect to taste, which 

 depends on many elements, but partly on habit and partly 

 on a love of novelty, there seems no improbability in animals 

 admiring for a very long period the same general style of ornamen- 

 tation or other attractions, and yet appreciating slight changes 

 in colours, form, or sound. 



Summary of the Four Chapters on Birds. — Most male birds are 

 highly pugnacious during the breeding-season, and some possess 

 weapons adapted for fighting with their rivals. But the most 

 pugnacious and the best armed males rarely or never depend for 

 success solely on their power to drive away or kill their rivals, but 

 have special means for charming the female. With some it is the 

 power of song, or of giving forth strange cries, or instrumental 

 music, and the males in consequence differ from the females in 

 their vocal organs, or in the structure of certain feathers. From 

 the curiously diversified means for producing various sounds, we 

 gain a high idea of the importance of this means of courtship. 

 Many birds endeavour to charm the females by low-dances or 

 antics, performed on the ground or in the air, and sometimes at 

 prepared places. But ornaments of many kinds, the most 

 brilliant tints, combs and wattles, beautiful plumes, elongated 

 feathers, top-knots, and so forth, are by far the commonest means. 

 In some cases mere novelty appears to have acted as a charm. 

 The ornaments of the males must be highly important to them, 

 for they have been acquired in not a few cases at the cost of 

 increased danger from enemies, and even at some loss of power 

 in fighting with their rivals. The males of very many species 

 do not assume their ornamental dress until they arrive at 

 maturity, or they assume it only during the breeding-season, or 

 the tints then become more vivid. Certain ornamental 

 appendages become enlarged, turgid, and brightly coloured 

 during the act of courtship. The males display their charms 

 with elaborate care and to the best ef ect ; and this is done in 

 the presence of the females. The courtship is sometimes a 

 prolonged affair, and many males and females congregate at an 

 appointed place. To suppose that the females do not appreciate 

 the beauty of the males, is to admit that their splendid decorations, 

 all their pomp and display, are useless ; and this is incredible 

 Birds have fine powers of discrimination, and in some few 

 instances it can be shewn that they have a taste for the beautiful. 

 The females, moreover, are known occasionally to exhibit a 

 marked preference or antipathy for certain individual males. 



Tf it be admitted that the females prefer, or are unconsciously 



