146 ASSOCIATION OF ORGANISMS THE WEB OF LIFE 



patches on the hinder part of the body are also of a vivid scarlet, 

 with a tinge of blue. The teeth are of formidable nature, as in 

 many apes and monkeys, the canines being particularly large, 

 partly ho doubt with reference to defence, but partly also in rela- 

 tion to combats with other males of the same species. The 

 female Mandrill is faded-looking in comparison to her mate. The 

 swellings on her face are comparatively small and pale, while 

 there is never more than a faint display of red. 



The attractions of male mammals often include a relatively 

 well -developed voice, as in the Red Deer, where during the 

 mating season the stag makes a characteristic roaring sound, 

 known as " belling", though whether this serves any special 

 purpose is doubtful. The last remark also applies, it would seem, 

 to the American Howling Monkeys, regarding one of which 

 Darwin thus speaks (in The Descent of Man): " The vocal 

 organs of the American Mycetes caraya are one-third larger in 

 the male than in the female, and are wonderfully powerful. These 

 monkeys in warm weather make the forests resound at morning 

 and evening with their overwhelming voices. The males begin 

 the dreadful concert, and often continue it during many hours, the 

 females sometimes joining in with their less powerful voices. An 

 excellent observer, Rengger, could not perceive that they were 

 excited to begin by any special cause; he thinks that, like many 

 birds, they delight in their own music, and try to excel each other." 

 One is irresistibly reminded here of the " dreadful concerts" held 

 nightly by the common Cat The males appear to take the 

 leading parts, and their unearthly cries seem to express defiance 

 of one another, rather than to be a means of attracting the softer 

 sex. 



COURTSHIP AND MATING OF BIRDS (AvES) 



THE LAW OF BATTLE. Most male birds are exceedingly 

 pugnacious, fighting for the possession of mates in the most 

 determined manner, the habit being perhaps best-marked in the 

 polygamous species. They may be provided with special 

 weapons, the spurs of cocks being a familiar example. The 

 methods of fighting of some birds are described as follows by 

 Brehm (in From North Pole to Equator): " Rival ostriches fight 

 with their strong legs, and, striking forwards, tear deep wounds 

 with their sharp toe-nails in the breast, body, and legs of their 



