PROTOMONADINA 



273 



Genus Trypanosoma Gruby. Parasitic in the circulatory system of 

 vertebrates; highly flattened, pointed at flagellate end, and bluntly 

 rounded, or pointed, at other; polymorphism due to differences in 

 development common; nucleus central; near bluntly rounded end, 

 there is a blepharoplast and usually a basal granule from which the 

 fl^gellum arises and runs toward opposite end, marking the outer 

 boundary of the undulating membrane; in most cases flagellum ex- 

 tends freely beyond body; many w^ith myonemes; multiplication by 

 binary or multiple fission. The organism is carried from host to 



In vertebrate 

 host 



Trypanosoma 



In invertebrate host 



Trypanosoma 



Crithidia 



Leptomonas 







Leishr 



Leptomonas and 

 Phytomonas (in plant) 



Leishmania 



Crithidia 



In vertebrate 

 host 



Herpetomonas 



Trypanosoma 



Fig. 119. Diagram illustrating the morphological differences among the 

 genera of Trypanosomatidae (Wenyon) 



host by blood-sucking invertebrates and undergoes a series of 

 changes in the digestive system of the latter (Fig. 120). A number of 

 forms are pathogenic to their hosts and the diseased condition is 

 termed trypanosomiasis in general. 



T. gamhiense Button (Fig. 121). The trypanosome, as it occurs in 

 the blood, lymph or cerebro-spinal fluid, is extremely active; body 

 elongate, tapering towards both ends and sinuous; 15-30^ by l-Sn; 

 the small blepharoplast is located near the posterior end; flagellum 

 arises from the blepharoplast and runs forward along the outer 

 border of somewhat spiral undulating membrane, extending freely; 

 binary fission; between long (dividing) and short (recently divided) 

 forms, various intermediates occur; in man in central Africa. 



