HOW ANIMALS EAT. 



55 



make use of their feet in securing prej', all four limbs be- 

 ing furnished with curved retractile claws; but the food 

 is conveyed into the mouth by 

 the movement of the head and 

 jaws. Man and the Monkeys em- 

 ploy the hand in bringing food 

 to the mouth, and the lips and 

 tongue in taking it into the cavi- 

 ty. The thumb on the human 

 hand is longer and more perfect 

 than that of the Apes and Mon- 

 keys ; but the foot of the latter 

 is also prehensile. 



2. The Mouths of Animals. 

 — In the Parasites, as the Tape- 

 worm, which absorb nourishment 

 through the skin, and Insects, as 

 the May-fly and Bot-fly, which do P'g. i9.-Arm of the ThnmWess 



,, , . . • , 1 1 1 i i. Monkey (Ateles). 



all tlieir eatmg in the larval state, 



the mouth is either wanting or rudimentary. The Amoeba, 

 also, has no mouth proper, its food passing through the 

 firmer outside part of the bit of protoplasm which consti- 

 tutes its body. Mouth and anus are thus extemporized, 

 the opening closing as soon as the food or excrement has 

 passed through. 



In the Infusoria the mouth is a round or oval opening 

 leading through the cuticle and outer laj'er of protoplasm 

 to the interior of the single cell which makes their body. 

 It is usually bordered with cilia, and situated on the side 

 or at one end of the animal. 



An elliptical or quadrangular orifice, surrounded with 

 tentacles, and leading directly to the stomach, is the ordi- 

 nary mouth of the Polyps and Jelly-fishes. In those 

 which are fixed, as the Actinia, Coral, and Hydra, tiie 

 mouth looks upward or downward, according to the posi- 

 tion in which the animal is attached (Figs. 38, 191, 207): 



