138 



HANDBOOK OF PROTOZOOLOGY 



A. Trypanosoma in Man 



Trypanosoma gamhiense Dutton (Fig. 49, a). Parasitic in 

 the blood and lymph of man in certain regions of Africa; trans- 

 mitted by the tsetse fly, Glossina palpalis. Reservoir hosts are 

 domestic and wild animals. Body 15 to 30 microns long. 

 Mature forms are slender and long, and shows a long flagellum; 

 individuals formed by longitudinal fission are short and broad 

 with no projecting flagellum. Half-grown forms are inter- 

 mediate in size and structure. The organism is responsible for 

 the "sleeping sickness" of man in Africa. 



Fig. 49 Mammalian trypanosomes as seen in stained smears. XlOOO. (After 



various authors). 

 a, five individuals of Trypanosoma gamhiense and an erythrocyte of man; 

 b, T. cruzi; c, T. brucei; d, T. theileri; e, T. melophagium ; f, T. evansi; g, T. 

 equinum; h, T. equiperdum; i, T. lewisi. 



Trypanosoma cruzi (Chagas) ( = Schizotrypanum cruzi Cha- 

 gas) (Fig. 49, h). Parasitic in children in South America (Bra- 

 zil, Peru, Venezuela, etc.). The trypanosome is a small curved 

 form, measuring about 20 microns in total length. With a 

 centrally located nucleus. A large blepharoplast is located 

 close to the sharply pointed non-flagellate end. Multiplication 

 takes place in the cells of nearly every organ of the host body. 

 Upon entering a host cell, the trypanosome loses its flagellum 

 and undulating membrane, and assumes a leishmania form 

 which measures 2 to 5 microns in diameter. This form under- 

 goes repeated binary fission, and a large number of daughter 



