ETIOLOGY 



239 



Fig. 55. Coccus 

 form of Piroplasma 

 bigemintim. 



disease certain of the red corpuscles contain pale or brighter 



pyriform shaped bodies. One end of each 

 body is broad and rounded, the other taper- 

 ing and pointed. Usualh- there are two of 

 these bodies, both of the same size in a cor- 

 puscle. More rarely there is but one, 

 although four are occasionally observed 

 (Fig. 57). 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 ob.served to change their position within the 

 red corpuscle. Smith has noted that the amoeboid bodies 

 observed w^ere apparently single within the corpuscle. In 

 dried and heated cover-glass preparations stained with alka- 

 line methylene blue, these parasites are colored distinctly. They 

 are also stained with carbol fuchsin and with hemotoxylin. 

 As a rule they stain more deeply in pre- 

 parations made for internal organs than 

 they do in those from the living blood. 

 In the capillaries of the congested 

 organs, the blood corpuscles contain 

 many more parasites. Smith has noted 

 in one case from 2 to 3 per cent of in- 

 fected corpuscles in the circulating blood 

 but in cover-glass preparations made at 



the autops}' quite different results, viz. : 



, , 11-1 1 ui 1 f n. Fig. 56. Blood from 



in the skeletal muscles, blood 01 the ... , 



kidney showing para- 



right heart, and blood from the bone mar- ^^^^^ ^j- xexas fever. 

 row (.sixth rib) very few infected corpus- {Smith). 

 cles ; in the blood from the left heart and lung tissue from 2 

 to 3 per cent of infected corpuscles ; in the spleen 5 per cent ; 

 in the liver and kidney tissue from 10 to 20 per cent ; and the 

 hyperemic fringes of the omentum and the heart muscle 50 

 per cent of the corpuscles were infected. In other cases the 





