PROTOMONADINA 245 



most cases flagelliim extends freely beyond body; many with 

 myonemes; multiplication by binary or multiple fission. The or- 

 ganism is carried from host to host by blood-sucking invertebrates 

 and undergoes a series of changes in the digestive system of 

 the latter (Fig. 113). A number of forms are pathogenic to their 

 hosts and the diseased condition is termed trypanosomiasis in 

 general. 



T. gambiense Button (Fig. 114, a). Parasitic in blood and lymph 

 of man in certain regions of Africa; transmitted by the tsetse fly, 

 Glossi7ia palpalis; reservoir hosts are domestic and wild animals. 

 Body 15-30m long; mature forms slender and long, w^th a long 

 flagellum; individuals formed by longitudinal fission short and 

 broad with no projecting flagellum; half-grown forms intermediate 

 in size and structure; the cause of the "sleeping sickness" of man 

 in Africa. 



T. (Schizotrypanum) cruzi (Chagas) (Fig. 114, h). Parasitic in 

 children in South America (Brazil, Peru, Venezuela, etc.). A 

 small curved form about 20/i long; nucleus central; blepharoplast 

 large, located close to sharply pointed non-flagellate end; multi- 

 plication takes place in the cells of nearly every organ of the host 

 body; upon entering a host cell, the trypanosome loses its flagel- 

 lum and undulating membrane, and assumes a leishmania form 

 which measures 2 to 5yu in diameter; this form undergoes repeated 

 binary fission, and a large number of daughter individuals are 

 produced; they develop sooner or later into trypanosomes which, 

 through rupture of host cell, become liberated into blood stream ; 

 transmitted by the reduviid bug, Triatoma megista and allied 

 species; the diseased condition is known as "Chagas' disease." 

 Apparently the organism occurs in wood rats (Neotoma) and 

 meadow mice (Microtus) in south-western United States, trans- 

 mitted from host to host by the cone-nose or kissing bug, Triatoma 

 protracta (Kofoid and others). 



T. hrucei PHmmer et Bradford (Figs. 9, a; 114 c). Polymorphic; 

 15-30/i long (average 20^); transmitted by various species of 

 tsetse flies, Glossina; the most virulent of all trypanosomes; the 

 cause of the fatal disease known as "nagana" among mules, don- 

 keys, horses, camels, cattle, swine, dogs, etc., which terminates in 

 the death of the host animal in from two weeks to a few months ; 

 wild animals are equally susceptible; the disease occurs, of course, 

 only in the region in Africa where the tsetse flies live. 



