384 MICROBIOLOGY 



it Pyrosoma bigeminum* Species of this genus have been 

 found and described in nearly all of the domesticated animals. 



PIROPLASMA (PYROSOMA) BIGEMINUM SMITH AND KILBORNE. 



Synonym. Babesia bovis Starcovici. 3 



Place in nature. Smith and Kilborne discovered this or- 

 ganism to be the cause of the disease of cattle existing in the 

 southern part of the United States known as ' ' Texas fever. ' '* 

 It was found by Lignieres 4 in the disease of cattle in Brazil 

 known as "tristeza" or bovine malaria, and Hunt and Collins 5 

 found it in the malady known as tick fever in Australia. 



It was first reported by Smith and Kilborne that this or- 

 ganism was transmitted from the infected animal to the unin- 

 fected one through the medium of the cattle tick Boopliilits 

 annulatus* They also found that this organism passed 

 through the egg and into the young ticks that were hatched 

 from the eggs of ticks that had grown on infected cattle or on 

 those immunized to the disease such as are found in the tick- 



* The generic name Pyrosoma was assigned because of its pear- 

 shaped form and the specific name bigeminum was selected because 

 the organism usually appeared in pairs in the blood corpuscles. The 

 generic name Pyrosoma had already been given to a well-known 

 Ascidian genus and consequently it was changed to Piroplasma by 

 Patton in 1895. In the meantime Starcovici (1893) had given the 

 name Babesia bovis to the form described by Babes; and as this 

 form seems to be identical with that described by Smith and Kil- 

 borne the correct name of the genus would appear therefore to be 

 Babesia and the species parasitic in cattle should be called, accord- 

 ing to Starcovici, Babesia bigeminum. 



3 Starcovici. Centralbl. f. Bakt, Bd. XIV (1893) p. 1. 



* It is also known as Spanish fever, bloody murrain, tick fever,, 

 bovine malaria and hemoglobinuria. 



4 Lignieres. "La Tristeza," Buenos Ayres, 1890. 



5 Hunt and Collins. Kept, on Tick Fever. Brisbane, Australia,. 

 1899. 



* This genus was first described by Riley in 1868 as Ixodes bovis. 

 Curtice in 1891 (Jour. Comp. Med. and Vet. Arch., Vol. XII (1893) 

 p. 3-13, also Vol. XIII (1892) p. 1,) changed the generic name to 

 Boophilus (ox-loving). Recently Karsch's genus Margoropus has 

 been adopted as the correct name of the genus. 



