HISTORY 395 



Disappearanee after death. Trypanosoma disappear very 

 suddenly after the death of the host. Within two hours signs 

 of degeneration begin ; the parasites shrink, assume irregular 

 shapes and then disappear. Motile forms are rarely found 

 after two hours. 



Distribution in nature. Trypanosoma are not knovvti to 

 exist in nature outside of the bodies of living animals. They 

 have been found in the blood of a large number of species. 

 Now has found them m the blood of many birds. They 

 have been kept alive in blood or salt solution for a few hours. 

 Novy has succeeded in cultivating them, i. ... getting them to 

 multiply on an artificial culture medium. 



R 307 Historical sketch. There is a voluminous 

 literature on the trypanosoma from which the following brief 

 summarv was taken. In 1841, Valentin discovered hematozoa 

 in trout'(5a/;... fario~) and in 1842, Glugge found them in the 

 blood of frogs. In 1843, Gruby observed a flagellate infusorium 

 in frogs which he named Tr. sanguinis. Gruby has generally 

 been credited with the discovery of these forms. From 1843 

 to 1879 the organisms were found by many observers, not only 

 in frogs but in birds as well. 



In 1879-80, Lewis described trypanosoma found in rats in 



India Uter he states that they are identical with Ir. Evansr. 



In 1880 G. Evans discovered trypanosoma m the blood 



of horses suffering with surra, the well known disease o 



India He proved their causal relation to the affection. In 



x885,'steele confirmed Evans' work, and named the parasite 



SHrocheta Evansi. 



The work of Evans and Steele was followed by man> 

 interesting discoveries of trypanosoma especially in fish and in 



man. 



In .896, Rouget described Trypanosoma tound in tl,e 

 blood of a horse suffering from donrine. Wasdewsky and 

 Senn in ,899, confirmed Kougef s work and deternnned the 

 ™tho<.enic ac ion of this parasite for the horse. Laveran and 

 Msnil proposed the nan.e Tr. ,oug.,i for the parastte of 



