AVES 



585 



A brief summary of the orders of birds will be given in the follow- 

 ing pages. Some of the orders are divided into numerous families. 



Struthioniformes (Ostriches). — These are the largest known birds 

 and they are native to Africa, but they are growing in domestication 

 in numerous parts of the United States. The large eggs weighing 

 three or four pounds are laid in communal nests in the sand; they 

 are then incubated by the sun. The wings are very rudimentary, 

 and there are only two toes. 





Fig. 307. — Kiwi, or apteryx, a wingless bird from New Zealand which is about 

 the size of the domestic fowl and loolts lilce an overgrown chick. (From Krecker, 

 General Zoology, published by Henry Holt and Company, Inc., after Evans.) 



Rheiformes (Rheas). — This is another form of running bird. They 

 are partially feathered on the neck, have three toes, and inhabit 

 South America. 



Casuariiformes (Emus and Cassowaries). — These are flightless, 

 running birds with very small wings. The former inhabits Australia 

 and the latter New Guinea. The cassowaries, which are smaller than 

 ostriches and have shorter necks, have a headgear with bright colors 

 on the head and neck. 



Apterygifornies (Kiwis). — This is the fourth order of running, 

 flightless birds. The feathers of this form are hairlike. The kiwi is 

 about the size of a hen, but its wings are much reduced. It is noc- 

 turnal, and it makes a nest in a hole in the gromid. 



