ADAPTATIONS 



329 



r 



defense; (c) defense of young; (d) rivalry; (e) adjustment to 

 surroundings. 



For the purpose of capture of their prey, most carnivorous 

 animals are provided with strong claws, sharp teeth, hooked 

 beaks, and other structures familiar to us in the lion, tiger, 

 dog, cat, owl, and eagle. Insect-eating mammals have con- 

 trivances especially adapted for the catching of insects. The 

 ant-eater, for example, has a long sticky tongue which it thrusts 

 forth from its cylindrical 

 snout deep into the recesses 

 of the ant-hill, bringing it 

 out with its surface covered 

 with ants. Animals which 

 feed on nuts are fitted with 

 strong teeth or beaks for 

 cracking them. Strong teeth 

 are found in those fishes 

 which feed on crabs, or sea 

 urchins. Those mammals 

 like the horse and cow, that 

 feed on plants, have usually 

 broad chisellike incisor teeth 

 for cutting off the foliage, 

 and teeth of very similar 

 form are developed in dif- 

 ferent groups of plant-eating 

 fishes. Molar teeth are found 

 when it is necessary that the 

 food should be crushed or 



chewed, and the sharp canine teeth go with a flesh diet. The 

 long neck of the giraffe enables it to browse on the foliage of 

 trees in grassless regions. 



Insects like the leaf -beetles and the grasshoppers, that feed 

 on the foliage of plants, have a pair of jaws, broad but sharply 

 edged, for cutting off bits of leaves and stems. Those which 

 take only liquid food, as the butterflies and sucking bugs, 

 have their mouth parts modified to form a slender, hollow 

 sucking beak or proboscis, which can be thrust into a flower 

 nectary, or into the green tissue of plants or the flesh of animals, 

 to suck up nectar or plant sap, or blood, according to the 

 special food habits of the insect. The honey-bee has a very 



FIG. 189. The brown pelican, showing gular 

 sac which it uses in catching and holding 

 fishes for its food. 



