DIVISIONS OF BIRDS. 



291 



are extremely powerful, and the hinder toe is wanting in all except 

 the Apteryx, in which it is present in a rudimentary condition. The 

 front toes (tig. 206, C and E) are either two or three in number, and 

 are furnished with strong blunt claws or nails. The feathers present 

 the remarkable peculiarity that the barbs, instead of being connected 

 by means of the barbules, are disconnected and separate from one 

 another, thus coming to resemble hairs in appearance. 



The African Ostrich (Struthio camelus), which is one of the best- 

 known members of this order, inhabits the desert plains of Africa 

 and Arabia, and is the largest of living birds, attaining a height of 



Fig. 206. — Morphology of Cursores. A, Sternum of the Ostrich (Struthio cameivs) : 8 

 Scapula ; c Coracoid. B, Side view of the pelvis of the Ostrich : i Iliuui ; p Pubis ; 

 is Ischium ; / Femur. C, Foot of Apteryx australis. D, Tarso-metatarsus of the 

 Apteryx, showing the hallux placed high up on its posterior surface. E, Foot of 

 the Rhea americana. 



from six to eight feet. The head and neck are nearly naked, and 

 the quill-feathers of the wings and tail have their barbs wholly 

 separate, constituting the ostrich-plumes of commerce. The legs 

 are extremely strong, and the feet have only two toes each. The 

 Ostriches run with extraordinary speed, and can outstrip the fastest 

 horse. They are polygamous, each male having several females, 

 and they keep together in larger or smaller flocks. The American 

 Ostriches or Rheas are much smaller than the African Ostrich, and 

 have the head feathei-ed, whilst the feet are furnished with three 

 toes each. They inhabit the great plains of tropical America, and 

 are polygamous. The Emeu {Dromaius) is exclusively confined to 



