NATUKE OF CELLS 



15 



a pseudoporlium. The entire sulistance of the amoeba then 

 slowly streams forward upon this false foot. Another 

 pseudopodium is put out, the streaming movement of the 

 body takes place again, and by a succession of these move- 

 ments, tlie amwba creeps about from place to place. 



Manner of obtaining food and digestion. — Whenever a 

 p.seudopodium or any part of the Ijody comes in contact 

 with a desii'able bit of food, the latter is gradually sur- 

 rounded and ingulfed, as it were, liy the body mass (Fig. 5). 

 The ingested bit of plant is then gradually digested and 



Fig. 5. — Series of diagrams showing an amceba eating a minute plant. 

 After Vcrworn. 



made a part of the protoplasmic mass, that is, assimilated. 

 The amti'ba has no stomach or special organs of digestion, 

 but any part of the botly can take in and tUgest the food. 

 The particles of ingested footl are usually surrounded by 

 a layer of water that is taken in at the same time. Gener- 

 ally several of these balls of food with their enveloping films 

 of water may be seen in the body. They are called the 

 food vacuoles. 



Elimination of waste matters. — The solid, undigested 

 portions of the food are thrust out of the body into the water 

 through temporary openings in the ectoplasm. These parti- 

 cles of solid matter are usually eUminated from that portion 

 of the protoplasm in the rear part of the moving animal. 



