Protozoan Cattle Fever. Texas Fever. Paluiism of Cattle. 589 



after a study of the organisms, named them Hcsmatococcus . The 

 following year Theobald Smith found them in the Texas fever 

 blood, and recognized them as protozoa (Pirosoma btgeminuni) . 

 Wadoleck proposed Apiosoma, Bonome AmcEbosporidia, and 

 Patton, Piroplasma. The latter pointed out that Pirosoma was 

 already in use for another organism. Th. Smith's discovery 

 identified Texas fever with the Roumanian hsemoglobinuria, and 

 stimulated the Bureau of Animal Industry to an extended re- 

 search which, in the main, elucidated the true nature of the dis- 

 ease. In a long series of experiments the observers produced 

 the disease in healthy susceptible cattle, by injecting them, in 

 the warm season with the blood of sick animals, and as con- 

 stantly failed in the experimental inoculation of similar blood on 

 non-bovine animals such as sheep, rabbits, Guineapigs and 

 figeons. In Australia, Pound had violent fever in two injected 

 sheep but no pyroplasma, and their blood injected on the ox, had 

 no affect. In none of these latter were the blood-globules in- 

 vaded by the parasite, nor were the corpuscles lessened in 

 number. In the affected cattle, the red cells were reduced from 

 the normal 7,000,000 per cubic mm. to 1,800,000 and even lower 

 in some cases. 



The Piroplasma Bigeminum passes through a series of forms in 

 the blood. Theobald Smith found in the red globule and attached 

 X.0 \\.s raax'gva 2l pale round body 0.5/11 in diameter, and staining 

 freely in alkaline methylene blue and other basic anilin dyes and 

 in hesmatoxylin, but not in acid coloring fluids. These he found 

 in the red globules in acute cases, often in company with the pear- 

 shaped bodies, and usually in the absence of the piriform bodies 

 in chronic cases, in non-fatal relapses, in cases occurring in cooler 

 weather, (late autumn or early winter) and in immune southern 

 cattle. The red cells containing these rounded organisms were 

 not crenated nor distorted, though 50 per cent, of them might 

 contain the parasite. He looked on these as the earlier stage of 

 the organism which later developed into the piriform body, by 

 segmentation of its substance. The piriform or spindle-shaped 

 bodies were usually found in pairs connected at their pointed ends 

 by a filament and extending across nearly the whole breadth of 

 the red globule. Free microorganisms, pear-shaped or round, he 

 failed to find in the blood of the large vessels; but saw them 



