112 WILD TRAITS IN TAME ANIMALS. 



nowhere find huge beasts, such as elephants or 

 hippopotami, living upon the tops of ranges of 

 hills. In the first place, they would not there 

 find nutriment enough to supply their needs ; and, 

 secondly, their bulk would preclude that agility 

 of movement so indispensable to the mountaineer. 

 The ass is grey in colour, as are nearly all the 

 dwellers among the rocks. As a rule, by study- 

 ingr the coloration of animals we can sfet some 

 very valuable hints as to their habits and history. 

 Generally speaking, animals are of such a hue as 

 renders them least conspicuous when among their 

 natural surroundings. There are striking excep- 

 tions to this rule ; but when such exist, we find 

 that there are special circumstances which account 

 for them. For instance, the zebra is very con- 

 spicuous when seen in broad daylight, and the 

 reason is found in the fact that zebras are banded 

 together in large herds and live on bush-covered 

 plains. Now, a herd of animals which cannot 

 adopt the sentry system generally guards against 

 the approach of an enemy, not so much through 

 each member watching for himself, as through 

 all individuals keeping a keen watch on one 

 another. Supposing a lion or a leopard were 

 perceived by one zebra ; his excited movements 



