676 MURIEL ROBERTSON. 
rare appearance on the sealed slide of blood direct from the 
Kmyda vittata. 
At this stage of the investigation the question of the 
transmitting host came to be considered. ‘This was the 
more difficult to determine as no parasites of any kind had 
been found on the milk tortoises. The aquatic habit of the 
tortoise pointed to some water inhabiting blood-sucking 
form, and of these the leeches seemed the most likely. A 
number of the common Ceylon water leech, called by the 
natives Diya kudella,! were investigated, but none of them 
showed any sign of the trypanosome. It was found, how- 
ever, that the leech fed readily upon the tortoise. Upon 
puncturing the crop immediately after feeding it was seen 
that the Trypanosomes began to undergo the above-described 
transformation at once upon being taken into the crop. 
Thus a leech was put on toa milk tortoise at 8.50 a.m. ; 
at 10.30 it was still feeding ; at 11.30 it was found free in 
the tank. The crop was punctured at once, and the blood 
examined in the usual way on a slide ringed with vaseline. 
The Trypanosomes were for the most part already casting off 
their flagella, and many of them had already undergone the 
first division. By 1 o’clock they were divided into four, and 
many of the resulting Herpetomonas forms had become free, 
and were swimming about on the slide. Blood was then 
taken from another part of the crop, and the state of the 
parasites was exactly similar to that on the sealed slide. 
The puncturing of the leech does not apparently cause it 
much inconvenience. ‘I'he specimen mentioned lived quite 
well till the next day, when I finally opened it at 7.30 a.m. 
Many actively motile forms in the Crithidial stage were to be 
seen. 
Further divisions it seems may occur after the two men- 
tioned, and also a secondary increase in size. Some of the 
individuals had become considerably lengthened, and were 
' Mr. W. A. Harding, who kindly examined the leeches brought from 
Ceylon, considers this leech to be Limnatis (Poecilobdella) granu- 
losa. 
