STUDIES ON CEYLON H#MATOZOA. 667 
found in the oviduct of a freshly-captured Emyda. There 
were five eggs but none of them hatched out, and Mr. Fer- 
nando, the taxidermist of the museum, who had, he told me, 
frequently tried similar experiments, said that he had never 
got eges obtained in this way to hatch out. It might possibly 
be that the length of time that the egg spent in the oviduct 
before being laid had some effect upon its capability for 
further development. One of the eggs was opened after 
more than three weeks, and although it was quite well pre- 
served no development had taken place. 
As a rule the Hmyda was fairly well infected and in some 
cases the blood contained a very large number of parasites. 
I may say at the outset that in spite of the most diligent 
search and of a slight theoretical bias in favour of the hypo- 
thesis I could not find any connection between the Trypano- 
some and the Hemogregarine infections. I propose to discuss 
the Hemogregarine in a subsequent paper. 
As far as my observation goes this Trypanosome is only 
found in Emyda vittata and I have called it Trypano- 
soma vittate. A Trypanosome is found in the fish Sacco- 
branchus (see ‘Some Ceylon Hzematozoa,”’ Drs. Castellani 
and Willey, ‘ Quart. Journ. Micr. Sci.” vol. 49, 1905), which 
inhabits similar localities, but this is obviously a quite dis- 
tinct species. Nicoria trijuga, though often to be found 
living side by side with Emyda vittata, and also as in 
the Colombo lake in water which harboured a very large 
number of the generally infected Saccobranchus, never 
showed any sign of a trypanosome infection at all. My 
own observations upon blood parasites in Ceylon and those of 
many observers upon the European forms, especially those 
occurring in birds and amphibians, point towards the neces- 
sity of exercising considerable care before deciding that any 
hematozoon is specific to any given vertebrate host. Never- 
theless, in the present instance I feel considerable confidence 
in attributing the Trypanosome in question exclusively to 
Emyda vittata. 
Trypanosoma vittate is a large form resembling 
