STUDIES ON CEYLON HAMATOZOA. 681 
animal feeds again in nature. An apparently empty leech 
will sometimes quite refuse not only to feed, but to remain 
on the tortoise. Nevertheless, from observations on captive 
leeches, it does not appear to me to be more than a few days. 
The Glossiphonia show a marked tendency to get into the 
less-exposed corners of the body, such as the folds of skin at 
the back of the neck, round the limb bases, and under the 
tail. They were actually seen to enter the cloacal chamber 
which is a relatively large cavity in these tortoises. 
The Glossiphonia, in contrast to the horse-leech, shows the 
Trypanosome very frequently in nature, in fact, the majority 
of the specimens are infected. And the parasite persists in 
empty leeches where no coloured matter is to be detected in 
the alimentary tract. I was never able to find the very 
earliest stages of the parasite in this leech owing to the diffi- 
culty of manipulation. It was neither easy to get the leech 
in a condition willing to feed nor to catch it at exactly the 
right moment after feeding. ‘This was, of course, due to its 
small size and wandering habits correlated with the exceeding 
rapidity of the early changes in the ''rypanosome. 
In the most recently-fed animals at my disposal the para- 
site was already in the shape of a rather broad flagellate 
approaching the crithidial condition—the first two divisions 
had, in most cases, already occurred. 
Thus a Glossiphonia which had fed on infected blood at 
some time between 8 a.m. on April 6th and 7 a.m. on April 
7th was opened just after the latter hour. The ’rypanosomes 
were already mostly in the shape of crithidia, but a very few 
were still in the rounded state just completing division. Some 
long slender forms, very narrow, with pointed posterior end, 
and the flagellum only reaching back to a little more than the 
middle of the body were already present. This indicates that 
the development is even more rapid than in the horse-leech. 
These long forms were not, I think, left over from the pre- 
vious meal as they were of a type not usually found at the 
end of digestion. 
The course of the infection in the Glossiphonia appears to 
VoL. 55, PART 4,—NEW SERIES. 48 
