26 TUF, GAMF. OF RRITIF^H EAST AFRICA. 



Another example of this broken distribution is that of the roan, found in small 

 numbers near the Ilhanga Hills and north-east of the Athi Plains. He next occurs 

 on the Guas Ngishu at the other side of the Rift valley, and also plentifully on 

 the German border. Between these spots, as far as I am aware, he is unknown. 



Now as to the special causes, natural or otherwise, influencing the game of 

 East Africa. 



I have said that such causes are chiefly : — 



(i.) Climatic; (ii.) pasturage and food supply; (iii.) kind of country; and (iv.) 

 the habits of other animals and mankind. I will take these in order. 



(i.) Climatic Conditions. 



Climatic conditions may affect an animal indirectly in many ways, most of which 

 are probably but imperfectly understood. The direct effects of heat and cold are 

 often, however, obvious, especially in the manner in which they affect hair in 

 mammals and feathers in birds. As a general rule, animals inhabiting a tropical 

 country are brilliantly coloured, while those of a temperate country are clad in more 

 sombre hues. At the equator there is a broad band of tropical vegetation running 

 round the globe. In this band the vegetation is rich and luxuriant, and there is a 

 wealth of animal and bird life. It is in this equatorial belt that animal life and birds 

 especially are found of such gorgeous colours. In Africa this belt contains the forest 

 lands of East Africa, Uganda, and the Ituri and Congo forests. The corresponding 

 tropical belt in the American continents is Central America and the richly luxuriant 

 regions of the Amazons. 



North and south of the tropical equatorial band are intermittent belts of desert 

 and barren countries, where there is but a paucity of animal life, usually of more 

 sombre coloration, as befits the habitat. In Africa these desert regions comprise, 

 amongst others, the Haud, Nubian, and Sahara deserts to the north, and the 

 Kalahari to the south. The Rob al Khali of Arabia, the desert regions of India and 

 China, and the salt lakes of Utah are amongst those that complete the northern 

 belt ; while to the south are the desert regions of Patagonia and Australia. Again, 

 north and south of this necklace of deserts are found the semi-tropical and temperate 

 belts. This is the general arrangement of the surface of the globe, though subject 

 to local variations. 



In addition to the effect of climate on the coloration of animals, the direct 

 effect of cold is usually to increase the growth of hair. This is generally, but not 

 always, the case. 



It appears that animals of the same species which inhabit both hot and cold 



