XXIII. BIRDS (continued) 



Chordata {continued) 



Ostriches and cassowaries. — The ostriches and casso- 

 ^\'al•ies are wholl}' unable to fly and are, therefore, known a^ 

 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 unkeeled. 

 This is in keeping with 

 their small, fimctionless 

 wings. The majority of 

 these birds are large and 

 possess strong legs with 

 which they can kick 

 \'iciously anrl effectively 

 and run swiftly. 



The true ostriches hve 

 on the sandy plains of 

 South Africa and Ara- . 

 bia. Unhke 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 lai-gest 

 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 hoi-se. Its wings ai'e rudimentary and it dcjes not 



279 



Fig. 1S9. 



