Protozoan Cattle Fever. Texas Fever. Paludism of Cattle. 545 



road and the Kansas farmers along this route suffered severe 

 losses, as well as those to whom the southern cattle were finally 

 distributed (Bra}'). 



Causes. Up to 1889 the true cause of Texas fever was un- 

 known. It was well established that cattle brought from the low- 

 lauds of the southern states, during the warm season, though 

 themselves in apparently the best of health, proved deadly to 

 northern cattle with which they came in contact, to those that 

 followed them in the same pasture during the same warm season, 

 and even in many cases to the mountain cattle of the south. In 

 the same way northern cattle, removed to the infected regions in 

 the south, contracted the fever and almost all perished. This 

 was equally true of cattle taken from the northern states to 

 Jamaica or other islands in the Gulf. In the winter season, after 

 the first severe frosts of autumn and before the last keen frosts of 

 spring, the southern cattle could be safely introduced into the 

 northern states and on this a modus vivendi, for a trade in 

 southern cattle in the winter only, was based. 



Microbiology. Piroplasma bigeminum : Apiosoma bigeminum. 

 (Apios pear, geminus twin). In 1888 Starcovici discovered pyri- 

 form \ organisms (Babesia bigeminum) in the red blood-globules 

 of Roumanian cattle suffering from haemoglobinuria, and Babes, 

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

 following year Theobald Smith found them in the Texas fever 

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

 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 haemoglobinuria, 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, Guinea pigs and 

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

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

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

 35 



