274 
SEXUAL SELECTION MAMMALS. 
Part II.. 
CHAPTEE XVIII. 
Secondary Sexual Characters o ^ l ^ KmjLKL ^— continued . 
Voice — Eemarkable sexual peculiarities in seals — Odour — Deve- 
lopment of the hair — Colour of the hair and skin — Anomalous 
case of the female being more ornamented than the male — 
Colour and ornaments due to sexual selection — Colour acquired 
for the sake of protection — Colour, though common to both 
sexes, often due to sexual selection — On the disappearance of 
spots and stripes in adult quadrupeds — On the colours and 
ornaments of the Quadrumana — Summary. 
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 giraffe and porcupine,^' are said to be completely 
mute excepting at this season. As the throats {i,e. the 
larnyx and thyroid bodies of stags become periodi- 
cally 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 
Owen, ‘Anatomy of Vertebrates/ vob iii. p. 585. 
- Ibid. p. 595., 
