PART II 

 REPTILES 



CHAPTER X 

 CROCODILES 



THE reptile class includes the crocodiles, turtles, tortoises, 

 lizards, and snakes. The members of the various orders 

 agree generally in the low temperature of their blood, 

 and in the outer layer of skin taking the protective form 

 of bony plates or scales. Reptiles belong to an earlier 

 period of the world's history than either mammals or 

 birds, and, with simpler organs than either, their 

 nervous systems and intelligence are also of a lower 

 grade. 



THE EGYPTIAN CROCODILE. This is the common 

 crocodile of tropical Africa. Its range now extends from 

 the upper Nile, through the rivers and lakes of central 

 Africa, to the Tugela in the south-east. It formerly 

 occurred a good deal north and south of these limits ; but 

 at the present day is certainly rare outside of them. It 

 seems never to have existed in the streams draining the 

 south and south-west districts of south Africa outside 

 the tropics. Probably the cool atmosphere of the high 

 southern tableland and of the south coast barred its 

 progress from the east, while the dry countries of the 

 south-west may have offered an impediment upon that 

 side of the continent. It is essentially a lover of tepid 

 tropical waters, and, extended on a sand-bank or rock, 



