CONCLUDING OBSERVATIONS. 355 



the first part of Chapter XII.) for flight in the air ; while 

 the fishes are so constructed ( 353-357) as to swim eas- 

 ily in the water. And then, in those classes of birds that 

 are designed in part for life on the water, there are spe- 

 cial provisions for swimming in their webbed feet and 

 other arrangements ( 291). Some animals are carnivo- 

 rous, while others are herbivorous, and others still eat a 

 variety of food, and may even be omnivorous, like man. 

 The adaptation of organization in these different cases 

 has reference, as you have seen, both to the kind of food 

 and to the mode of obtaining it. If it had reference 

 merely to the former, it would be seen only in the teeth, 

 the jaw, and the stomach. But in its reference to the 

 latter, it is observed in the structure and arrangement of 

 the organs of the senses, and even of the whole frame. 

 For example, in the carnivorous animal of prey, there 

 must be a full development of the senses of sight, hear- 

 ing, and smell ; a frame capable of quick movement ; 

 strong claws, worked by stout muscles, to hold the prey ; 

 teeth fitted to tear it in pieces, and a stomach altogether 

 different from that of the herbivorous animals. 



619. The adaptations in relation to temperature are 

 very interesting. Animals that live in cold climates have 

 coverings which differ greatly from those of animals liv- 

 ing in warm countries. The elephant, with his scanty 

 hairs, is in strong contrast in this respect with the shag, 

 gy-coated bear. Our supply of furs comes from north- 

 ern regions, from animals that could not withstand the 

 cold without such coverings. As the horse is a native 

 of a warm climate, he requires the blanket in our winters, 

 and for the same reason the cow and ox need to be bet- . 

 ter sheltered than is ordinarily done among the farmers- 

 of temperate climates. In the arctic regions, even ani- 

 mals that are protected by a furry covering have also, as 

 a farther defense against the cold, a good layer of fat, 

 which not only keeps the heat in by its non-conducting 

 property, but also aids in the production of heat. We 



