CxiAP. XVIII.] VOCAL ORGANS. 261 



CHAPTER XVIII. 



Secondary Sexual Characters of Mammals — continued. 



Voice. — ^Eemarkable Sexual Peculiarities in Seals. — Odor. — Development 

 of the Hair. — Color of the Hair and Skin. — Anomalous Case of the 

 Female being more ornamented than the Male. — Color and Ornaments 

 due to Sexual Selection. — Color acquired for the Sake of Protection. — 

 Color, though common to both Sexes, often due to Sexual Selection. — 

 On the Disappearance of Spots and Stripes in Adult Quadrupeds. — 

 On the Colors and Ornaments of the Quadrumana. — Simimary. 



Quadrupeds use their voices for various purposes, as 

 a signal of danger, as a call from one member of a troop 

 to another, or from the mother to her lost offspring, or 

 from the latter for protection to their mother ; but such 

 uses need not here be considered. We are concerned only 

 with the difference between the voices of the two sexes, 

 for instance, between that of the lion and lioness, or of the 

 bull and cow. Almost all male animals use their voices 

 much more during the rutting-season than at any other 

 time ; and some, as the gu-affe and porcupine,*, are said to 

 be completely mute excepting at this season. As the 

 throats (i. e., the larnyx and thyroid bodies'*) of stags be- 

 come periodically enlarged at the commencement of the 

 breeding-season, it might be thought that their powerful 

 voices must be then in some way of high importance to 

 them ; but this is very doubtful. From information given 

 to me by two experienced observers, Mr, McNeill and Sir 

 P. Egerton, it seems that young stags under three years 



1 Owen, * Anatomy of Vertebrates,' vol. iii. p. 585. ' Ibid. p. 595. 



