ETIOLOGY 



353 



o 



Fig. 89. 



Plroplasma bigeminum in red blood 

 corpuscles. 



that Plroplasma is the proper generic term and this is used by 

 writers on protozoa. 



If Texas fever in America and hemoglobinuria in Rou- 

 mania are ident- 

 ical, Babes was 

 the first to call 

 attention to the 

 existence of this 

 intraglobular 

 parasite. It seems that Dr. Stiles, in 1867, observed this or- 

 ganism but failed to recognize its significance. It is found in 

 the blood in cases of Texas fever and it also exists in the 

 blood of immune animals in the tick infested districts. The 

 life history of this parasite is not determined. In the blood 

 of the diseased animals they appear in the unstained, fresh 

 preparation, as minute or larger bright bodies which may be 

 from 0.5 to A.ofJ. in diameter according to the form of the 

 disease. In the acute types of the disease certain of the red 

 corpuscles contain pale or brighter pyriform shaped bodies. 

 One end of each body is broad and rounded, the other tapering 

 and pointed. Usually there are two of 

 these bodies, both of the same size, in a 

 corpuscle. More rarely there is but one, 

 although four are occasionally observed 

 (Fig. 91). When two are present the 

 tapering ends approach each other and 

 usually they are joined while the other 

 ends may point in any direction. Several 

 forms have been noted varying from a 

 round to a pyramidal outline. The small 

 and often the larger bodies have been 

 observed to change their position within 

 the red corpuscle. Smith has noted that the ameboid bodies 

 observed were apparently single within the corpuscle. In 

 dried and heated cover- glass preparations stained with alka- 

 line methylene blue, these parasites are distinctly colored. 

 They are also stained with carbol fuchsin and with hemo- 



FiG. 90. Coccus 

 fo rm of Piroplas- 

 ma bigeminum. 



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