472 



FAMILY: TRYPANOSOMIDiE 



Fig. 200. — Diagram of Life-Cycle of Trypanosoma lewisi in the Flea ( x 2,000). 

 (After Minchin and Thomson, 1915.) 



1. Trypanosome from rat's blood. 



2. Slightly modified trypanosome after few hours in flea's stomach. 

 3-12. Stages in intracellular multiplication. 



13-18. Two ways in which established rectal phase may arise from the stomach trypanosomes. 



19. Established rectal phase, showing haptomonads (/t),nectomonads (?i), transitional crithidia 



types (t.r.). and metacyclic trypanosomes (T). 



20. Secondary infection of the pyl(3ric region of the hind-gut, showing forms similar to those 



which occur in the rectum. 



