ANIMAL LIFE OF THE COUNTRY. 23 



or other causes, usually but imperfectly understood, are responsible for variations in 

 colour, size, length of hair and horn, and other changes. These influences which 

 tend to cause local variations are chiefly (i.) climatic ; (ii.) pasturage and food 

 supply ; (iii.) kind of country; and (iv.) the habits of the other animals and human 

 beings inhabiting such country. 



It may be presumed that when a new species of animal gradually comes into 

 existence its migrations are at first confined to such countries as are exactly similar 

 to those in which it originated. Any spreading of the species into different kinds 

 of country must be a slow process of gradually becoming accustomed to the altered 

 state of living. To explain more clearly, I will suppose that the rhino in the 

 highlands of East Africa is now passing through such a change. In East Africa 

 the animal spends his time between plain and bush. In the plain he is easily 

 brought to bag, as he can be seen from afar, and, owing to his defective eyesight, 

 he can be approached to within a short distance and often be shot dead before 

 he is aware of his danger. In the bush things are much more in his favour, as, 

 it being impossible to locate him by sight, he has the chance of winding or hearing 

 an adversary. Moreover, most people are rather careful to avoid him there, for 

 one might easily approach within a few yards of him without being aware of his 

 presence. Then a rapid charge, and the chances are in favour of the rhino bringing 

 the hunter to bag. The animal's weight also gives him a great advantage over his 

 pursuer in the bush, for he can crash rapidly through the thickest of bush and 

 thus put a mass of difficult country between himself and the hunter. Following 

 in his footsteps is no easy matter, as the stiff thorn branches which he has pushed 

 aside so easily spring back into their old positions across his track and 

 bar the way. 



Again, if he has been disturbed by wind the chances are that he will make off 

 downwind, and so you must either follow in his wake, with the certainty of giving him 

 your wind again as soon as you get near him, or attempt to make a detour through 

 previously unbroken bush and chance hitting him off. 



Now, in process of time, if the rhino is spared long enough to effect the 

 change, he should become, in this country, a pure bush animal, shunning the open 

 plains entirely. His pursuit will then be more or less akin to that of the Central 

 African rhino. 



It cannot be expected that such a change could be effected at once ; it would 

 be a long process. 



The rhino is dependent on certain grasses and foods which he gets from the 

 plains, and which are probably as necessary to his diet as are the thorns of the bush. 



