TEXAS FEVER 329 
fever and it also exists in the blood of immune animals in the tick 
infested districts. The life history of this parasite has not been 
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 4.0% in diameter according to the form of the 
disease. In the acute types 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. 78). 
When two are present the tapering ends approach each other and 
usually they are joined while the other ends may point in any direc- 
tion. Several forms have been noted varying from a round to a 
pyramidal outline. The small and often 
the larger bodies have been observed to i 2 {| 
change their position within the red «5: C) 
corpuscle. Smith has noted that the 
ameboid bodies observed were appar- 
ently single within the corpuscle. In 
dried and heated cover-glass prepara- 
tions, stained with alkaline methylene 
blue, these parasites are distinctly 
colored. They are also stained with 
earbol fuchsin and with hemotoxylin. 
As a rule they stain more deeply in Fic. 77. COVER-GILASS PREPARA- 
preparations made from parenchy- tion rroM KIDNEY. CORPUS- 
matous organs than they do in those Oe 
from the living blood. 
In the capillaries of the congested organs, the blood corpuscles con- 
tain many more parasites. Smith has noted in one case from 2 to 3 
per cent. of infected corpuscles in the circulating blood but in cover- 
glass preparations made at the autopsy from the skeletal muscles, 
blood of the right heart, and blood from the bone marrow (sixth 
rib) very few infected corpuscles were found. In the preparations of 
blood from the left heart and lung tissue from 2 to 3 per cent. of the 
corpuscles were infected; those from the spleen 5 per cent.; from the 
liver and kidney tissue from 10 to 20 per cent.; and in the hyperemic 
fringes of the omentum and the heart muscle 50 per cent. of the 
corpuscles were infected. In other cases the blood corpuscles in the 
capillaries were more and in still others less extensively invaded. In 
