42 THE COURTSHIP OF ANIMALS 



endeavours to discover the whereabouts of females 

 desiring mates. Of necessity roaming far in search of 

 food, the unmated have no means of making their where- 

 abouts known, save by thus giving tongue to desire. 

 Evidently the normal methods of voice production do not 

 suffice for their urgent needs, for the carrying power of 

 the voice is immensely fortified by means of great air 

 sacs, or chambers, formed in part by an enlargement 

 of the body of the hyoid, or the bone which supports 

 the tongue, and in part by dilatations of the inner walls 

 of the larynx. The females, it is to be noted, are by 

 no means so well equipped in this matter. It is not 

 necessary that they should be. All that those desiring 

 mates have to do is to follow up the cries of avid males, 

 a by no means difficult task, especially when under the 

 spell of the emotions which possess them. But the 

 mechanism which serves the Chimpanzee and the Gorilla 

 by no means fulfils the needs of the Orang-utan. In this 

 uncouth creature the system of resonating chambers is 

 immensely increased by great, thin-walled, membranous 

 pouches extending round the neck and under the arm- 

 pits, so that when inflated these areas have a most extra- 

 ordinarily swollen appearance. When the Orang chooses 

 to lift his voice even the deaf must hear. 



Where fighting instead of fondling is the sequel to 

 these impassioned cries the conflict is probably not of 

 long duration, for it is certainly severe. This is attested 

 by the fact that captured specimens, if adult, are com- 

 monly found to be minus one or more fingers, which have 

 been bitten or torn off in these love affairs. 



An added ferocity of expression is given to the male 

 Gorilla by the development of enormous brow ridges 

 and the huge canines. The former are regarded by some 



