180 ECONOMIC ZOOLOGY 



Zealand, Fig. 113, the Rheas or South American Ostriches, and the 

 Struthiones or African Ostriches, Fig. 114, to be discussed later. 

 In the Carinatae are included the vast majority of modern birds. 

 The division is named from the deep[keel-like sternum possessed by 

 most of them which possess the power of flight. While the ostriches 

 owe their safety to their large size and powers of rapid terrestrial loco- 

 motion, and the kiwis to their isolation on the Island of New Zealand, 

 the carinatae, which are usually of comparatively small size, owe their 

 safety to their almost universally highly developed power of aerial 

 flight. It is this power that also enables them to perform their annual 

 migrations and thus better preserve their own lives and that of their 

 young. This migration of birds is one of the most interesting subjects 

 in the field of zoology and its bibliography is very extensive. 



FIG. 113. A kiwi, Apteryx australis. xKo- (From Hegner, College Zoology, 



after Evans.) 



In a few of the Carinatae, the Penguins, for example, the wings are 

 developed into paddle-like organs for swimming under water and the 

 power of aerial flight is entirely lacking. A few of the countless species 

 of birds of economic importance will now be discussed, most of which 

 species will obviously belong to the division Carinatae. 



The Ostrich. Only the African ostrich, Struthio camelus, will be 

 discussed here, since the Rheas or South American ostriches are of 

 much less importance, though they are hunted by the natives almost 

 to the point of extinction, their feathers being useful for dusters and 

 other purposes. They are smaller than the African forms but have 

 similar habits. 



The African ostrich originally inhabited all of the more or less desert 

 parts of the Dark Continent and certain regions of Southern Asia. 



