OF THE ALIMENTARY TRACT 9 



then, serve the purpose of locomotion or of food 

 gathering or both. 



Protozoa are voracious feeders. They live to eat 

 to multiply. 



Some have no apparent mouthpiece but may en- 

 gulf solid particles through a seemingly unbroken 

 ectoplasm. Pseudopodia or ectoplasmic processes 

 from any part of the body may wrap themselves 

 around a food body and enclose it much as flowing 

 water will surround a stone. 



Some absorb foods in solution. 



Some hav6 stomata (mouth) which to most ob- 

 servers may appear more imaginary than real. They 

 may be merely specialized surfaces through which 

 food particles are taken when they are brushed against 

 them by food gathering organelles. These mouth- 

 pieces are usually depressed at least. 



Others have more definite stomata w^hich may be 

 readily seen and recognized as pores or orifices. Food 

 materials are thrown into them by flagella or cilia. 



Foods of various kinds, bacteria, yeasts, molds, 

 other protozoa, starch granules, crystals, materials 

 from the tissues of the host, liquids, etc., are thus 

 ingested through the ectoplasm and are swallowed, 

 so to speak, into the interior of the body, the endo- 

 plasm (inner substance). 



Here they are brought into contact with the se- 

 cretions, the digestive juices. Usually there is formed 

 about on-e or more of these swallowed substances a 

 cavity into which is poured the digestive fluid. 



