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 no 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 Zhe Descent of Man):—‘ The vocal 
organs of the American MMycetes 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) 
Tue Law or Battite.—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 #vom 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 
