IOO THE MEANING OF EVOLUTION 



birds lies somewhere between one hundred and five de- 

 grees and a hundred and ten. Creatures which are 

 warmer than their surroundings must have some pro- 

 tection against chilling. Accordingly both mammals 

 and birds have clothing. In the case of mammals 

 the covering is fur, in the case of birds feathers. In 

 some of the tropical animals like the elephant and 

 rhinoceros, or in man, who has learned to protect him- 

 self in cold regions by making clothing for himself, 

 this hair is very short, and except where serving for 

 ornament is quite scanty, no longer being of use as a 

 protection. But the great majority of all mammals 

 are well covered with a dense coat of hair. In many 

 of those living in the colder regions there is in reality 

 a double coat. The fur seal of the Alaskan Islands is 

 so provided. A set of long hairs deeply fastened in 

 the skin forms a covering, which shows on looking 

 at the seal. Underneath this layer, and set but lightly 

 into the skin, is a short coat of very much finer hair 

 known as the underpelt. When the skin is taken from 

 the seal it is split by machinery into a lower and an up- 

 per layer. When so split the deep-seated pits of the 

 long hairs are cut, and these hairs come out. The fine 

 underpelt thus laid bare is what is commonly known 

 as sealskin. Fashion has decreed that this must be 

 dyed a rich brown, although when taken from the 

 animal it is nearly mouse gray. 



