CHAPTER XLI 

 PATHOGENIC PROTOZOA OF THE MASTIGOPHORA 



(Exclusive of the Spirochetes) 



THE pathogenic forms of the class Mastigophora differ from 

 the preceding in that they do not possess pseudopodia. In most 

 cases the organism has a relatively definite form. The cells are 

 motile by means of one or many flagella. 



This class contains many hundreds of species distributed 

 among many genera and families. Most of these are non-parasitic. 

 Many species are commensals in the intestines of man and animals, 

 and have been suspected of producing intestinal disorders. 



The protozoan genera, Spirocha?ta, Treponoma, and Spiro- 

 schaudinnia, probably belong with the Mastigophora, and show 

 some distinct resemblances to the genus Trypanosoma. Their 

 position among the protozoa, however, is challenged by many 

 bacteriologists. They are, therefore, treated as a separate group 

 in the succeeding chapter. 



(1) Cell-bodies a flexuous, narrow spiral ...... Spiroch&ta (Chapter XLII). 



(2) Cell-bodies not as (1) : 



An undulating membrane and terminal flagellum 

 present ......................................... Trypanosoma. 



Undulating membrane not present ................. Herpetomonas. 



THE GENUS TRYPANOSOMA 



The first recorded observations of trypanosomes are those of 

 Valentine, who saw -them in the blood of a salmon in 1841. 

 Numerous observers found similar organisms in the blood of other 

 fish, reptiles, and batrachia. Lewis, in 1878, observed the first 

 trypanosome of mammalian blood in the rat. Evans, in 1880, 

 noted them in the blood of animals infected with surra, and be- 

 lieved them to be the cause of the disease. Bruce, in 1894, de- 



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