206 Evolution and Adaptation 



present in both sexes. In the shrew mice, abdominal scent 

 glands are present, but since these mice are rejected by birds 

 of prey, their glands probably serve to protect them ; " never- 

 theless the glands become enlarged in the males during the 

 breeding season." In many other quadrupeds the scent 

 glands are of the same size in both sexes, and their func- 

 tion is unknown. 



" In other species the glands are confined to the males, or 

 are more developed than in the females ; and they almost 

 always become more active during the rutting season. At 

 this period the glands on the sides of the face of the male 

 elephant enlarge, and emit a secretion having a strong musky 

 odor. The males, and rarely the females, of many kinds of 

 bats have glands and protrudable sacs situated in various 

 parts ; and it is believed that these are odoriferous. 



" The rank effluvium of the male goat is well known, and 

 that of certain male deer is wonderfully strong and persist- 

 ent. Besides the general odor, permeating the whole body 

 of certain ruminants (for instance, Bos moschatus) in the 

 breeding season, many deer, antelopes, sheep, and goats, 

 possess odoriferous glands in various situations, more es- 

 pecially on their faces. The so-called tear-sacs, or subor- 

 bital pits, come under this head. These glands secrete a 

 semifluid fetid matter which is sometimes so copious as to 

 stain the whole face, as I have myself seen in an antelope. 

 They are ' usually larger in the male than in the female, 

 and their development is checked by castration.' According 

 to Desmarest they are altogether absent in the female of 

 Antilope subgutturosa. 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 {Moschus 

 moschifcrus), a naked space round the tail is bedewed with 

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

 male until two years old, this space is covered with hair, and 



