90 Natural TJieology. 



thick layer of blubber beneath the skin, giving pro- 

 tection from the cold and buoyancy in the waters. 

 This burden of fat, which would weigh down a land 

 animal, is a float to one moving only in the ocean. 



Thus we find one animal perfectly fitted for bur- 

 rowing in the earth, and he comes out smooth and 

 unsoiled as does the mole from the sand and dirt. 

 One delights in heat, another can endure nothing 

 warmer than icy water or the iceberg itself. The 

 walrus and seal, the whale, the polar bear and rein- 

 deer, all find a home in the icy north, and each has 

 a mode of life and structure peculiar to itself. But 

 the form, the organic structure, the food, the adapta- 

 tion to climate, and the instincts, all harmonize. 

 Each animal is a study by itself ; each one is won- 

 derful in the harmony of its relations to the world. 



Not only are animals fitted for every zone, but by 

 their organic structure or functional change they 

 are fitted for the change of seasons. As winter 

 approaches, Nature thickens the coating of fur ; and 

 when spring returns, she plucks out the surplus 

 coating to fit them for the summer months. For 

 those animals, like the bat, the marmot, and the 

 bear, whose food fails in the winter, Nature pro- 

 vides as for the reptiles already mentioned. They 

 enter their dens as winter approaches, and a deep 

 sleep falls upon them ; a sleep by which the vital 

 action is changed. The circulation becomes slow, 

 the temperature of the body lowered, and the ani- 

 mal, with its vitality reduced to the lowest point, 

 lives upon its own fat till spring calls him forth 



