MAMMALS. 605 



ment is checked by castration."* According to Desmarest, 

 they are altogether absent in the female of Antilope sub- 

 gutturosa. Hence, there can be no doubt that they stand 

 in close relation with the reproductive functions. They 

 are also sometimes present, and sometimes absent, in nearly 

 allied forms. In the adult male musk deer {MoscUus mtrs- 

 chiferiis) a naked space round the tail is bedewed* with an 

 odoriferous fluid, while in the adult female, itftd' 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 additional scent-organ. It is a singular faei. 

 that the matter secreted by this latter gland does not,, 

 according to Pallas, change in consistence or increase in 

 quantity during the rutting - season ; nevertheless, this' 

 naturalist admits that its presence is in some way con- 

 nected with the act of reproduction. He gives, however, 

 only a conjectural and unsatisfactory explanation of its. 

 use. t 



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

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

 allur.e the female. We must not judge on this 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 odor serves to bring the females from a dis- 

 tance to the males. Active and long-continued use cannot 

 here have come into play, as in the case of the vocal organs. 

 The odor 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 open- 

 ing the orifice, have in some cases been developed. The 

 development of these organs is intelligible through sexual 

 selection if the most odoriferous males are the most suc- 



*Owen, " Anatomy of Vertebrates," vol. iii, p. 632. See also Dr. 

 Murie's observations on these glands in the " Proc. Zoolog. Soc.," 

 1870, p. 340. Desmarest, on the Antilope subgutturosa, ' ' Mammal- 

 ogie," 1820. p. 455. 



f Phallas, " Spicilegia Zoolog,," fasc. xiii, 1799, p. 24; Desmou- 

 lins, "Diet, Class. 4'I^t Nat.," torn, iii, p. 586, 



