296 
Flagellates in Fleas 
EXPLANATION OF PLATE III. 
All figures drawn under oil-immersion T V' Zeiss, ocular 4. Figs. 2 and 3 are drawn to 
a scale ^ less than the other figures. 
Figs. 1—-15. Herpetomonas ctenophthalmi. 
Fig. 1. Adult flagellate with intact flagellum. 
Fig. 2 (a, b and c). Flagellates, showing reduction of flagellum. 
Fig. 3. Radiate group of flagellates. 
Fig. 4 (a and b). Forms with diffused chromatin : (b) shows unequal division. 
Figs. 5-11. Stages of encystation. 
Fig. 12. Degeneration of nucleus (?). 
Fig. 13. Formation of chromidia. 
Fig. 14 (a). Cyst with dividing nucleus ; (b) cyst with no apparent nucleus. 
Fig. 15. Small flagellate without nucleus. 
Figs. 16-27. Crithidia hystrichopsyllae. 
Fig. 16. Large flagellate. 
Fig. 17. Flagellates in last stage of division. 
Fig. 18. Slender flagellate. 
Fig. 19 (a and 6). Small flagellates with no apparent nucleus. 
Fig. 20. Group of encystiug forms in process of division. 
Figs. 21-26. Stages of encystation : in Fig. 21 the nucleus is dividing : in Fig. 25 the 
flagellum is doubled. 
Fig. 27. Large cyst in division. 
