OF DIGESTION. 109 



same purpose, (Figs. 61-64.) Many Annelides, the leeches 

 for example, have a sucker, which enables them to produce 

 a vacuum, and thereby draw out blood from the perforations 

 they make in other animals. Many microscopic animals are 

 provided with hairs or cilia around the mouth, (Fig. 65,) 

 which by their incessant motion produce currents that bring 

 within reach the still more minute creatures or particles on 

 which they feed. 



225. Among the Vertebrata, the herbivora generally em- 

 ploy their lips or their tongue, or both together, for seizing 

 the grass or leaves they feed upon. The carnivora use their 

 jaws, teeth, and especially their claws, which are long, sharp, 

 even movable, and admirably adapted for the purpose. The 

 woodpeckers have long, bony tongues, barbed at the tip, 

 with which they draw out insects from deep holes and crevi- 

 ces in the befrk of trees. Some reptiles also use their tongue 

 to take their prey. Thus, the chameleon obtains flies at a 

 distance of three or four inches, by darting out his tongue, 

 the enlarged end of which is covered with a glutinous sub- 

 stance to which they adhere. The elephant, whose tusks 

 and short neck prevent him from bringing his mouth to the 

 ground, has the nose prolonged into a trunk, which he uses 

 with great dexterity for bringing food and drink to his mouth. 

 Doubtless the mastodon, once so abundant in this country, 

 was furnished with a similar organ. Man and the monkeys 

 employ the hand exclusively, for prehension. 



226. Some animals drink by suction, like the ox, others 

 by lapping, like the dog. Birds simply fill the beak with 

 water, then, raising the head, allow it to run down into the 

 crop. It is difficult to say how far aquatic animals re- 

 quire water with their food ; it seems, however, impossible 

 that they should swallow their prey without introducing at 

 the same time some water into their stomach. Of many 

 among the lowest animals, such as the Polyps, it is well 



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