the Weasel in winter, render these animals less visible 

 to their enemies when snow covers the ground. 



The study of coloration among existing mammals 

 has led to the conclusion that the primitive pattern con- 

 sisted of either transverse or longitudinal stripes, and 

 that it was probably the latter. Many mammals have 

 young that are spotted or striped one w^ay or the other, 

 but these stripes and spots disappear as the animal 

 grows older. The striped patterns are generally sup- 

 posed to have been adapted to forest conditions. 



The fact that certain moths invariably rest on 

 trees, against which they are extremely difficult to see, 

 and the fact that many other forms seek the back- 

 grounds against wiiich they are inconspicuous, prompts 

 the writer to be reticent in casting aside the idea of a 

 purposive character in nature. It must be remembered 

 that many other Zoologists are not willing to accept, 

 in its entirety, the theory that all coloration is purely 

 Physiological. There is still considerable evidence of 

 purely protective colors which seem to be the object 

 of a purposive creation. 



The Habitats of Mammals 

 The mammals present a very interesting assort- 

 ment of preferences in choosing places in w^hich to live 

 and build their homes. Some of them have specially 

 adapted structures which determine the sort of habi- 

 tats in which they are to be found. Mammals may be 

 classified as Terrestrial, Arboreal, Aquatic and Aerial. 

 Terrestrial animals include those that live on or under 

 the ground. Animals that live in trees are Arboreal; 

 flying animals, such as bats, are Aerial. Those forms 

 like the whales, seals and dolphins, which are structur- 



-*H[ 28 ><*- 



