PLATE XX 
microns 
Fig. 3. Prowazekella lacertae. The forms figured at a, c and e show the appearance of the attachment of the 
“trailing 5 ’ flagellum. In others both flagella appear to be quite free. The series n to x shows what is 
probably the conjugation and encystment, while t to y show the first nuclear division of the zygote and the 
formation of the vacuole. At j and k are two cysts corresponding to that at o. Later stages of the cyst develop¬ 
ment are shown at m, l and i in which nuclear multiplication to the 32 nuclear stage is reached. At all stages 
the parabasal bodies are seen surrounding the nucleus and they are roughly divided into two groups at nuclear 
division both of the free Hagellates and the encysted forms. (C. M. M\ del.) 
