CHAPTER VII 



THE CLOTHING OF MAMMALS 



THE subject of the external covering of the body of the animals 

 which make up the class mammalia has so far been but very 

 briefly touched upon, and this for the reason that it demands 

 a whole chapter to itself. 



While birds present an absolute uniformity in the matter 

 of the covering of the body, the mammalia exhibit the widest 

 possible differences in this respect ; the range and nature of these 

 differences are herewith to be briefly outlined. 



In the majority of mammals the surface of the body is pro- 

 tected from the extremes of temperature by a covering of more 

 or less thread-like, horny outgrowths of the skin, known as hair. 

 Unlike the feathers of birds, the hair of mammals is, in the first 

 place, uniformly distributed over the body; and, in the second, 

 may become profoundly modified, so as to assume the forms which 

 we know respectively as wool, bristles and spines. But, besides, 

 the bodies of some mammalia are encased in yet other and more 

 markedly peculiar outgrowths of the skin, to be described presently. 



The hair, it should be noted, may assume different characters 

 in the same animal, as in the horse, for instance, where, along the 

 ridge of the neck, and on the tail, it becomes greatly lengthened 

 and coarse in character, forming what are known as the mane 

 and tail, while in some breeds of domesticated horses it grows 

 to an extreme length on the lower part of the legs. In many 

 animals the hair assumes a peculiarly soft and often velvety 

 character, and this is known as fur. In many fur-bearing 

 animals, and in some others, which would normally be described 

 as ' hairy," there is found beneath the outer coat a short 

 inner coat of fur, and this is known as the " under-fur." The 

 fur of the seal is of this latter kind, while squirrel, sable, bear 

 and fox fur is formed by the outer coat. 



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