53° TIi€ Descent of Man. Paut u 



odoriferous fluid, whilst in the adult female, and in the male 

 until two years old, this space is covered with hair and is not 

 odoriferous. The proper musk-sack of this deer is from its 

 position necessarily confined to the male, and forms an additioiial 

 scent-organ. It is a singular fact that the matter secreted by 

 this latter gland does not, according to Pallas, change in con- 

 sistence, or increase in quantity, during the rutting-season ; 

 nevertheless this naturalist admits that its presence is in some 

 way connected with the act of reproduction. He gives, however, 

 only a conjectural and unsatisfactory explanation of its use.'^ 



In most cases, when only the male emits a strong odour 

 during the breeding-season, it probably serves to excite or allure 

 the female. We must not judge on tliis head by our own taste, 

 for it is well known that rats are enticed by certain essential 

 oils, and cats by valerian, substances far from agreeable to us ; 

 and that dogs, though they will not eat carrion, sniff and roll on 

 it. From the reasons given when discussing the voice of the 

 stag, we may reject the idea that the odour serves to bring the 

 lemales from a distance to the males. Active and long-continued 

 use cannot here have come into play, as in the case of the vocal 

 organs. The odour emitted must be of considerable importance 

 to the male, inasmuch as large and complex glands, furnished 

 with muscles for everting the sack, and for closing or opening 

 the orifice, have in some cases been developed. The develop- 

 ment of these organs is intelligible through sexual selection, if 

 the most odoriferous males are the most successful in winning 

 the females, and in leaving offspring to inherit their gradually- 

 perfected glands and odours. 



T)ev:'lopm<:nt of the Bair. — We have seen that male quadrupeds 

 often have the hair on their necks and shoulders much more 

 developed than the females; and many additional instances 

 could be given. This sometimes serves as a defence to the male 

 during his battles ; but whether the hair in most cases has been 

 specially developed for this purpose, is very doubtful. We may 

 feel almost certain that this is not the case, when only a thin 

 and narrow crest runs along the back ; for a crest of this kind 

 would afford scarcely any protection, and the ridge of the back 

 is not a place likely to be injured ; nevertheless such crests are 

 sometimes confined to the males, or are much more developed 

 in them than in the females. Two antelopes, the 'I'ragcla/.lun 

 Btripdus" (see fig. 70, p. 544) and Furtax picta, may be given as 



'* Pallas, 'Spi.ilegiaZoolog.'t'asc. " Dr. Gray, ' Gleanings from th« 



siii. 1799, p. 24; L^csni'iulins, ' Diet. Mnnagerie at Knowsley,' jjl. 28. 

 Class. d'Hist, Nat.' toir. ii;. p. 586. 



