THE OSTRICH. 135 



vegetation of the Indian Archipelago. The Emeu is con- 

 fined to the great Australian Continent, and the Rhea to 

 the southern extremity of the Western Hemisphere. And 

 finally, returning homewards, we find the Bustard, the 

 largest bird of this quarter of the globe, receding, it is 

 true, in some particulars, from the typical form, but still 

 fairly to be regarded as the representative of the family 

 in Europe. Some species, however, belong to the same 

 group with this latter bird, and extend themselves over a 

 considerable portion both of Africa and Asia. 



The principal external characters by which the birds 

 above enumerated are connected together, consist in the 

 absence of the hind-toe, of which not even a vestige re- 

 main; in the length and power of their legs, which are 

 completely bare of feathers ; in the shortness of theii 

 wings, and their uselessness as organs of flight ; in the 

 length of their necks ; and in their strong, blunt, flattened 

 bills. The plumes of the more typical among them are 

 distinguished by the want of cohesion between their barbs, 

 a cohesion which, in other birds, is manifestly subservient 

 to the purposes of flight, and which would, therefore, have 

 been superfluous in these, which never raise themselves 

 above the surface of the ground. Their food is almost 

 entirely vegetable, and consists of seeds and fruits, or, 

 rarely, of eggs and worms. Between the crop, which is 

 of enormous size, and the gizzard, which varies in thick- 

 ness and power, several of them are furnished with an 

 additional ventricle, analogous to the structure which pre- 

 vails in Ruminating Quadrupeds. They occupy a station 

 in some degree intermediate between the Rasorial Birds 

 and the Waders, approaching the latter in many particu- 

 lars of their outward form, but much more closely con- 

 nected with the former in their internal structure, in their 

 food, and in their habits. 



Of the differential characters which give to the Ostrich 

 the rank of a genus, the most important is founded on the 



