ON TRYPANOSOMA AND THEIR PRESENCE IN 
THE BLOOD OF BRISBANE RATS. 
By C. J. POUND, F.R.M.S. 
(Govt. Bacteriologist) 
(Read before the Royal Society of Queensland, 3rd Sept., 1904) 
Dvrine the past four years I have examined large numbers 
of rats of different species for plague, and occasionally in 
the systemic blood of some of the rats I detected the pre- 
sence of those peculiarly interesting micro-parasites. the Try- 
panosomas. These organisms were first discovered by T. R. 
Lewis in India in 1879. He describes them as occurring in 
the blood of rats and hamsters which were apparently healthy. 
At first he thought they were spinila, but on closer examin- 
ation he found they possessed a distinct body outline, with 
at one end a flagellum. Lewis’s original drawings of these 
organisms, which appear in the Quarterly Journal of Micro- 
scopical Science for that year, are somewhat primitive, com- 
pared with the same organisms seen with present day instru- 
ments. Lewis depicts them as having cylindrical or bi- 
tapering bodies. one end of which continued into a long lash- 
like thread. They were detected in twenty-nine per cent. of 
the species of rats Mus decumanus and Mus rufescens, and 
although from their movements and general appearance they 
resembled organisms of bacterial origin, Lewis considered 
they were more closely related to the Protozoa. 
In 1880, Dr. G. Evans, of the Army Veterinary Depart- 
ment in India, discovered the presence of a Trypanosoma 
c 
