FOOD OF AMCEB.E 145 



order to ensure the adequate nourishment of every 

 part of the cell, the food in process of digestion is 

 made to circulate through the body of the amoeba 

 until finally, its power of yielding nourishment being 

 exhausted, the body of the animal flows away from 

 the debris and leaves it behind. 



The actual food material varies considerably. The 

 Amoebae inhabiting water, mud, or moss seem to live 

 almost entirely on minute forms of vegetable life 

 such as algae, though relatively large ciliates have 

 been observed on some occasions in the bodies of the 

 amoebae of moss. Amoebae inhabiting the human 

 intestine vary again with respect to food. 

 nutrition alters according to the situation in which 

 they are found. Those that are capable of pene- 

 trating deeply into the mucous membrane, and even 

 into the submucosa, feed on the de"bris of the cells 

 they invade, and some even ingest red blood- 

 corpuscles. The forms occupying the alimentary 

 canal are commonly termed Entamcebce, and En- 

 tamceba histolytica and E. teiragena (most probably 

 two forms of the same organism, though till recently 

 believed to be quite distinct) have the power of 

 devouring numerous red blood-corpuscles. Bacteria, 

 and sometimes other Protozoa, are also seen in pro- 

 cess of digestion within the cells. The Entamcebce 

 that are not pathogenic, though they are parasites of 

 the alimentary canals of their hosts, do not seem to 

 have the power of feeding upon the blood-elements. 



All amoebae possess a nucleus. The minute 

 structure of the nucleus was a means by which 

 species of amoebae were defined, and was very im- 



