TRYPANOSOMES IN TSETSE-FLIES AND OTHER DIPTERA. 209 
Fries. 138-143.—From November 10th, 1905, second fly, black blood 
(p. 242). 
Fries. 144-150.—From November 10th, 1905, second fly, proctodeeum 
(p. 241). 
Fries. 151-155.—From November 13th, 1905, third fly, red blood (p. 
243). 
Fics. 156-164.—From November 13th, 1905, third fly, black blood (p. 
243). 
Fires. 165-170.—From November 18th, 1905, third fly, proctodeum (p. 
244); all drawn from the “ pure” smear, 
Fia. 171-173.—From November 14th, 1905, third fly, red blood (p. 
945). 
Fics. 174-176.—From November 14th, 1905, third fly, transition from red 
to black blood (p. 245). 
Fies. 177-182.—From November 14th, 1905, third fly, black blood (p. 
245). 
Figs. 183-185.—From November 14th, 1905, third fly, proctodseum (p. 
246). 
PLATE 12. 
Trypanosoma grayi. Stages of encystation and division (except 
Fig. 217). 
Fics. 186-203.—From November 14th, 1905, third fly, proctodaum (p. 
246). 
Fie. 186.—Ordinary young form. 
Figs. 187, 188.—Herpetomonas-like forms, free, not begun to form 
cysts. 
Figs. 189-193.—Forms in which the formation of the cyst and the re- 
tractation of the flagelum is proceeding. 
Figs. 194-198.—Forms in which the retractation of the flagellum and 
the formation of the cyst is more advanced.  l'igs. 194 and 195 show 
the condition with a flagellum vacuole. 
Figs. 199-202.—Ripe cysts. Fig. 202 is from a thin smear and is 
damaged ; the others are from a thick smear. In Figs. 200 and 201, z 
cannot be identified with certainty. 
Fic. 203.—Division proceeding within a cyst, which is ‘broken in 
making tle smear. 
Figs. 204-216.— From November 14th, 1905, third fly, transitional 
region between red and black blood (p. 245). 
