MAMMALS — VOCAL ORGANS. 521 



CHAPTER XVIII. 



SECONDARY SEXUAL CHARACTERS OP MAMMALS-continued. 



Volcer-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 orna- 

 ments due to sexual selection— Color acquired for the sake of pro- 

 tection-Color, though common to both sexes, often due to sexual 

 selection— On the disappearance of spots and stripes in adult quad- 

 rupeds—On the colors and ornaments of the Quadrumana— Sum- 

 mary. 



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; hut 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 (1. e. the larynx 

 and thyroid bodies^) of stags periodically become enlarged at the 

 beginning of the breeding-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 experienced observers, Mr. McNeill and Sir P. Egerton, it 

 seems that young stags under three years old do not roar or 

 bellow; and that the old ones begin bellowing at the commence- 

 ment of the breeding-season, at first only occasionally and mod- 

 erately, whilfet they restlessly v/ander about in search of the fe- 

 males. Their battles are prefaced by loud and prolonged bellow- 

 ing, but during the actual conflict they are silent. Animals of all 

 kinds which habitually use their voices utter various noises under 

 any strong emotion, as when enraged and preparing to light; 



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

 "Ibid. p. 595. 



