ADAPTATION 



233 



entirely toothless. The tongue serves to gather the multitude of 

 tiny insects which are necessary to nourish its seven-foot body, 

 and since ants are so small and soft, teeth are quite unnecessary. 

 The claws are incidentally effective weapons. 



Carnivorous Animals. Such animals, while they have special- 

 ized teeth, are no less dependent for food upon adaptations of the 

 appendages. The ability to stalk prey silently, to pursue it rap- 

 idly, and to spring upon it quickly must be brought into play 

 before the teeth are necessary to hold and kill, and the shearing 



.J \ 



Fig. 140. — Ant-bear, Myrmccophaga jubata. (Through the courtesy of the 



New York Zoological Society.) 



molars to cut through the relatively tough flesh as the prey is 

 eaten. 



Insects. In all forms of animals such adaptations are found. 

 Insects have mandibles whose strength is in proportion to the 

 harshness of their food. Species which live on fluids have the 

 primitive mandibulate mouth highly modified to form suctorial 

 structures, and in some cases piercing structures to enable 

 them to reach their food (Figs. 141 and 78). Both types of 

 mouth are found in both phytophagous and carnivorous in- 

 sects. In the latter some type of powerful grasping leg is also 

 present. 



Birds. Birds likewise have powerful hooked beaks and strong 

 claws if carnivorous and hooked beaks but weak claws if they eat 



