XXIII. BIRDS (continued) 



Chordata (continued) 



Ostriches and cassowaries. — The ostriches and casso- 

 waries are wholly unable to fly and are, therefore, known as 

 the flightless land birds. At the same time, they are the 

 lowest members of the class. The breastbones of these 

 large birds differ decidedly from that of the sparrow, for 

 they are flat, or nnkeeled. 

 This is in keeping with 

 their small, fmictionless 

 wings. The majority of 

 these birds are large and 

 possess strong legs with 

 which they can kick 

 viciously and effectively 

 and run swiftly. 



The true ostriches live 

 on the sandy plains of 

 South Africa and Ara- 

 bia. Unlike the spar- 

 row, the feathers in the 

 tail and wings of the 

 ostriches are long and plumehke and furnish the feathers 

 so commonly used for ornament. The ostrich is the largest 

 living bird, measuring from six to seven feet in height. It 

 has long, strong legs with two-toed feet and can run faster 

 than a horse. Its wings are rudimentary and it does not 



279 



Fig. 1S9. — Cassowar^^ 



