246 



PROTOZOOJ.OGY 



Fig. 113. The life-cycle of Trypanosoma lewisi in the flea, Cera- 

 tophyllus fasciattis (Minchin and Thomson, modified), a, trypanosome 

 from rat's blood; b. individual after being in flea's stomach for a few 

 hours; c-1, stages in intracellular schizogony in stomach epithelium; 

 m-r, two ways in which rectal phase may arise from stomach forms in 

 rectum; s, rectal phase, showing various types; t, secondary infection 

 of pylorus of hind-gut, showing forms similar to those of rectum. 



