PROTOZOA 233 



Protozoa. 

 Sarcodina. 



Rhizopoda. 



Amoebina Amoebae. 

 Mastigophora. 

 Flagellata. 



Monadida, Cercomonas, Trypanosoma, Poly- 



mastigida, Trichomonas. 



Some authors separate a family Spirochaetidae to in- 

 clude Spirochaeta and Treponema. 

 Sporozoa. 



Gr egarinida gr egarines . 

 Coccidia coccidia. 

 Hemosporidia. 



Plasmodium malaria. 

 Infusoria. 

 Cilia ta. 



Heterotrichida Balantidium. 



The protozoa are always, in every stage of development, primi- 

 tive unicellular bodies. They consist essentially of a cell body or 

 sarcode, a nucleus, and a nudeolus. All of the vital functions of 

 the cell are carried out by the cell body, the protoplasm of which 

 digests and assimilates food. Particular parts of the protoplasm 

 have special functions, these parts are called organdies. The 

 living protoplasm is finely granular, is viscid, and exhibits a dis- 

 tinct movement. The motility of protozoa is supplied variously. 

 In the Rhizopoda progression takes place by pseudopods or false 

 feet, a phenomenon in which a section of the cell wall and proto- 

 plasm are extended like a bud. Into this the latter then flows 

 with a shrinkage of the main body. At last the pseudopod is 

 large enough to- hold all the protoplasm and the former place of the 

 protozoon is vacated for the new. Motility is also supplied by 

 the lashing or vibratory action of flagella or the fine vibration of 



