470 PROTOZOA 



PHYLUM: PROTOZOA. 

 III. Class: Sporozoa. Leuckart. 



I. Subclass: Telosporidia. Schaudinn. 



I. Order : Coccidiomorpha. Doflein. 



I. Suborder: Coccidia. Leuckart. 



II. Suborder : Hfemosporidia. Danilewski em. Schaudinn. 

 II. Order: Gregarinida. Aime" Schneider em. Doflein. 

 I. Suborder : Eugregarinida. Doflein. 

 II. Suborder : Amoebosporidia. Aime* Schneider. 

 II. Subclass: Neosporidia. Schaudinn. 



I. Order: Cnidosporidia. Doflein. 



I. Suborder: Myxosporidia. Butschli. 

 II. Suborder: Microsporidia. Balbiani. 



II. Order : Sarcosporidia. Balbiani. 



Appendix : Serumsporidia, Haplosporidia, Lymphosporidia. 

 II. Subphylum: Ciliophora. Doflein. 

 I. Class: Ciliata. 



I. Order: Holotricha. Stein. 



II. Order: Heterotricha. Stein. 



III. Order: Oligotricha. Butschli. 



IV. Order: Hypotricha. Stein. 

 V. Order: Peritricha. Stein. 



II. Class: Suctoria. Butschli. 



So far only a few of the protozoa have been shown to produce dis- 

 ease in man; in the lower animals the number of pathogenic forms is 

 slightly larger, but the great majority seem to dwell as harmless para- 

 sites in the bodies of their hosts. 



The groups which are of medical interest are the following: The 

 amoebina 1 and the mycetozoa, from the class rhizopoda; the flagellata, 

 from the class mastigophora; the sporozoa as a class, and one order 

 from the ciliata. 



The Amoebina (Fig. 144) include forms composed of naked, simply 

 constructed protoplasm having the power of producing variously shaped 

 pseudopodia, or protoplasmic processes, which are used as organs of 

 locomotion and of nutrition. They possess generally one nucleus and 

 a contractile vacuole. 



The life cycle of only a few varieties has been studied, and until the 

 full cycle of development of any so-called amoeba is known it is impos- 

 sible to say whether it belongs among the rhizopoda, or whether it is 

 one of the forms of development of another group, as amoeboid forms 

 may occur at some time in the life history of all groups. According to 

 the few forms studied, the amoebse increase by (1) simple division and 

 by (2) encysting. In the latter case the nucleus divides into many 

 daughter-nuclei, which arrange themselves around the periphery, 2 and, 

 under favorable conditions, the protoplasm divides about them and 

 young amcebse are formed, leaving often a central mass of protoplasm, 

 or "crystal residuum" ("Rest Korper"). The young amoeba then 

 break through the cyst membrane and soon assume the forms of the 



i See figures under amoeba coli. 2 See figures under amoeba coli. 



