STUDIES ON CEYLON HA#MATOZOA. 677 
rather slender, but in almost every case the trophonucleus 
was posterior to the kinetonucleus. 
Another leech killed ninety-five hours after feeding on the 
same tortoise showed slender Crithidial forms in the crop and 
some irregularly-shaped individuals. ‘lhe intestine never 
showed many of the flagellates. A number of leeches were 
allowed to feed on various tortoises with the intention of 
observing the progress of the infection at different distances 
of time. Unfortunately, the work was at this point inter- 
rupted by illness for a number of weeks. On resuming it | 
found that the Trypanosomes still did persist in the crop in a 
few cases, but they were always very scarce. In one posi- 
tive case they were to be found six weeks after feeding. 
An experiment was tried by feeding a leech for a second 
time on infected blood to see if the second infection would 
persist in greater numbers than the first, but by some fatality 
the tortoise ate the specimen that | had in this condition, and 
I never made outit the parasite showed any signs of becoming 
acchmatised to the host. ‘lhe tortoise showed the greatest 
desire to eat the leeches, and had to be carefully watched ; 
even so, it was surprising how often the more lively Hmydas 
got the leech. They gulp them down, but do not break the skin 
with their teeth. ‘he leech seems rather difficult to swallow, 
but the tortoise is most persevering, and it is almost impos- 
sible to rescue the leech once the tortoise has got well started. 
I mention this, as there is always the possibility of para- 
sites being spread by way of the digestive tract. ‘he leech 
generally prefers to sit on the carapace attached by the 
posterior sucker and to fix its anterior sucker to the occiput, 
or back of the neck, or into the humeral angle. ‘The accom- 
panying text-figure is from a pencil sketch made in a few 
minutes by Dr. Willey, and gives a very typical picture. ‘I'he 
leech will stretch to an almost incredible extent when the 
tortoise puts out its head rather than let go. 
‘There is one point in the habits of this leech worthy of 
mention, namely, the tact that it will often feed in two 
instalments. Thus a leech would attach itself and feed for 
