126 
:\ruRrEL rorektson. 
little rod which sticks straight out from the anterior end of 
the organism. A very considerable time seems to elapse 
before it becomes motile, I cannot say exactly how long, but 
it seems to be moi’e than twelve hours. 
A leech (6n) opened six days after feeding showed a typical 
infection of the varied type so characteristic of Ponto- 
b del la. 
True Trypanosomes had already appeared, some of these 
Trypanosomes from the blood of the skate rounding off on a sealed 
slide. The drawings are from live si>ecimens. 
were broad individuals and others were much more slender, 
but not of the elongated type which appears at a much later 
stage of digestion. 'I’he broad and slender types were joined 
u}) by innumerable intermediate forms. Besides these crithi- 
dial forms were also present. I call crithidial forms those 
where an undulating membrane is developed, but which have 
not the typical Trypanosome arrangement of the kineto- and 
tropho-nucleus. Herpetomonad forms with the flagellum 
sticking straight out from the broad end of the body and 
with as yet no membrane were also to be seen. And finally 
Text-fig. 2. 
Text-fig. 3. 
