274 
SEXUAL SELECTION: MAMMALS. 
Part 
II. 
CHAPTER XVIII. 
Secondary Sexcjal Characters of Mammals — continued - 
Voice — Remarkable sexual peculiarities in seals — Odour — D eve ' 
lopment ol tire hair — Colour of the hair and skin — AuoieV-^ 
case ol the female being more ornamented than the mal e V 
Colour and ornaments due to sexual selection — Culour acq« irc ‘ 
foi the sake ol protection — Colour, though common to 
sexes, often due to sexual selection — On the disappearance 0 
spots and stripes in adult quadrupeds — On the colours :lJ,c 
ornaments of the Quadrnmana — Summary. 
Quadrupeds use tlieir voices for various purpo^J, 
as a signal of danger, as a call from one member ° [ 
a troop to another, or from the mother to her l°f 
offspring, or from the latter for protection to the' 1 ' 
mother; but such uses need not here be considered 
H'e are concerned only with the difference between 
voices of the two sexes, for instance between that 
the lion and lioness, or of the bull and cow. 
all male animals use tlieir voices much more duri^ 
the rutting-season than at any other time ; and 
as the giraffe and porcupine , 1 are said to be completed 
mute excepting at this season. As the throats (».«■ t ' lC 
larnyx and thyroid bodies 2 ) of stags become period' 
cally enlaiged at the commencement of the breedi IJ b 
season, it might be thought that tlieir powerful vofc^ 
must be tlien in some way of high importance to then 1 * 
but this is very doubtful. Prom information give 11 
me by two experienced observers, Mr. McNeill and S‘ r 
1 Owen, ‘Anatomy of Vertebrates,’ vol. iii. p. 585. 
