208 ESSENTIALS OF BACTERIOLOGY 



A blood-sucking fly, known as the Glossina palpalis, is con- 

 sidered the means of infection. The fly is closely related to 

 the Glossina morsitans, or tsetse fly. The sleeping sickness in 

 man is most likely the same thing as the nagana of cattle. 



Methods of Examinations. From Blood. A patient search 

 may fail to detect the organisms a large amount of blood, 

 10 c.c., obtained by venesection is centrifuged and the white 

 cells examined in hanging drop or stained smear. 



Cerebrospinal fluid will at times give results. 



Animal Inoculation. The blood of suspected person in- 

 jected into monkeys or rats and the resulting infection stu- 

 died by above methods. 



Staining. The organism is best stained by Giemsa stain 

 or the Romanowsky method. 



Trypanosoma Evansi (Steel, 1880). Pathogenic for all 

 animals. 



Discovered by Evans in the blood of horses suffering from 

 surra, a disease prevalent in India and the Philippine Islands. 

 The disease resembles nagana. 



T. equiperdum and T. Rougetii are names given to similar 

 organisms found in dourine, a disease affecting horses in 

 southern France and Spain. Trypanosomes are found in fish, 

 oysters, birds, and frogs, and many varieties have been 

 described. 



Herpetomonas (Leishman, 1903) (Leishman-Donovan 

 Bodies). A disease called variously kala-azar, dum-dum 

 fever, tropical splenomegaly, is considered to be due to an or- 

 ganism somewhat related to the trypanosomes. 



Smears are stained after fixation by the Wright or Roman- 

 owsky stains. Cultivation has succeeded on blood-media 

 made acid with citric acid. 



The bedbug is considered instrumental in transmitting the 

 organism. 



Piroplasma Bovis (P. Bigeminum) (T. H. Smith, 1893). 

 Origin. In the blood of animals suffering from Texas 

 cattle-fever. 



Form. A pear-shaped protozoon, found in pairs in the red 



