140 HANDBOOK OF PROTOZOOLOGY 



Trypanosoma equiperdum Doflein (Fig. 49, h). In horses and 

 donkeys. The cause of a chronic disease known as "dourine." 

 Widely distributed. Length 25 to 30 microns. No intermediate 

 host; transmission takes place directly from host to host during 

 sexual act. 



C. Trypanosoma in Other Mammals 



Trypanosoma lewisi (Kent) (Fig. 49, i). In the blood of 

 various species of the rat, Rattus. Cosmopolitan. Under 

 ordinary conditions, the trypanosome is not pathogenic to the 

 host. The organism which measures about 25 microns long, 

 is very active. It is slender and possesses a long flagellum. 

 Transmission by the flea, Ceratophyllus fasciatus, in the diges- 

 tive tract of which the parasite undergoes asexual reproduction. 

 When the infected fleas are eaten by a rat, the latter becomes 

 the victim of a new infection. 



Trypanosoma duttoni Thiroux. In the species of the mouse, 

 Mus. Similar to T. lewisi, but rats are not susceptible, hence 

 considered as a distinct species. Transmission by fleas. 



Trypanosoma peromysci Watson. Similar to T. lewisi. In 

 Canadian deer mice, Peromyscus maniculatus and others. 



Trypanosoma nabiasi Railliet. Similar to T. lewisi. In rab- 

 bits, Lepus domesticus and L. cnniculiis. 



D. Trypanosoma in Birds and Reptiles 



Trypanosoma paddae Laveran and Mesnil. In Java spar- 

 row, Munia oryzivora. 



Trypanosoma noctuae (Schaudinn). In the little owl, Athene 

 noctua. 



Several other species are known. 



Crocodiles, snakes, and turtles are hosts for Trypanosoma. 

 Transmission by blood-sucking arthropods or leeches. 



E. Trypanosoma in Amphibians 



Trypanosoma rotatorium (Meyer) (Fig. 50, a). In tadpoles 

 and adults of various species of the frog. Between a slender 

 form with a long projecting flagellum measuring about 35 

 microns long and a very broad one without free portion of the 

 flagellum, various intermediate forms are to be noted in a single 



