SEXUAL SELECTION 679 



CHAPTEE XVIII 



SEOONDAEY SEXUAL CHARACTERS OF MAMMALS— con^mwec? 



Voice— Remarkable 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 

 sezual 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 — Summary 



QUADETJPEDS 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 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 giraffe and porcupine, ' 

 are said to be completely mute excepting at this season. As 

 the throats {i.e., the larynx and thyroid bodies') of stags 

 periodically become enlarged at the beginning of the breed- 

 ing season, it might be thought that their powerful voices 

 must be somehow of high importance to them ; but this is 

 very doubtful. From information given to me by two ex- 

 perienced observers, Mr. McNeill and Sir P. Egerton, it 



' Owen, "Anatomy of Vertebrates," vol. iii. p. 585. 

 ' Ibid., p. 595. 



