THE ANIMAL KINGDOM. 37 



that of birds, has a sharp, keel-like ridge for the attach- 

 ment of the muscles which are to move the arms ; and 

 the shoulder-blades and the collar-bones, whic'h serve to 

 keep them apart, are both very strong. 



Bats are divided into several families, some of which 



> 



Fig- 44- 

 HEAD OF VAMPIRE BAT, 



live on fruits, others on insects, whilst a third group live 

 on the blood which they suck from other animals, and, as 

 in the other Mammalia, the teeth are arranged accord- 

 ingly. Thus, in the Spectre Vampiro the head of 

 which is annexed (Fig. 44), the molar teeth have pointed 

 tubercles, between which the hard coating of insects is 

 readily crushed ; whilst the sharp canine teeth serve to 



