46 



THE HEMOFIACELLATES 



b. Polymorphic (slender, intermediate and stumpy forms). 



(1) BRUCEI SUBGROUP 



Polymorphism constant (stumpy forms always present). 

 T. brucei of all domestic animals, antelope. 

 T. rhodesiense of man, bushbuck and probably antelope. 

 T. gambiense of man. 



(2) EVANSI SUBGROUP 



Polymorphism inconstant (stumpy forms rare or sporadic); no 

 cyclic development in vector host. 



(a) Transmission mechanical by insects. 



T. efflnsi of cattle, camels, equids, dogs, etc. 

 T. equinum of equids. 



(b) Transmission by contact (coitus) from mammal to mammal. 

 T. equiperdum of equids. 



II. PARASITES OF BIRDS 



Very polymorphic, sometimes attaining great size. Relatively easy to cultivate. 

 Cyclic development probably in biting arthropods. 



AVIUM GROUP 



T. avium of various birds. 

 T. calmettei of chickens. 

 T. gallinarum of chickens. 

 T. hannai of pigeons . 

 T. numidae of guinea fowl. 



Fig. 2. Species of Trypanosoma. A. T. llwilcri. B. T. cnizi. C. T. coiigoleiise. 

 D. T. vivax. E. T. equiperduvi . F. T. bnicei. X 2800. (Original) 



