162 BE. A. MINCHIN.. 
proventriculus, although I myself fell into the error of calling 
it the stomach in my communication. 
Our further studies were divided between us as follows: 
Gray and Tulloch continued the investigation of the “wild” 
trypanosomes. I confined myself to a study of the changes 
undergone by. Il’. gambiense when taken up by the tsetse- 
fly from infected animals. My intention was to work the 
development of T. gambiense from the beginning, so to 
speak, up to the condition found by Gray and Tulloch in the 
fresh-caught flies, and so link my researches on to theirs, with 
hope of thus getting the complete cycle. This expectation 
was not fulfilled, since more extended knowledge forced the © 
conclusion slowly, but irresistibly, upon us, that the “ wild ” 
trypanosomes had nothing whatever to do with T. gam- 
biense, but represented at least two distinct species occurring 
in the fly quite independently of sleeping sickness. As a 
result, however, of our subdivision of the work, my two | 
colleagues accumulated an abundant material of the “ wild” 
trypanosomes; my material of these interesting forms con- 
sists only of those found incidentally in flies used for experi- 
ments with T. gambiense, in all six flies having been found 
by me thus infected. 
I returned to England at the endl of 1905, leaving Gray 
and Tulloch still at work upon these problems. Our ever . 
increasing doubts as to the true nature of the wild trypano- 
somes led to our planning a number of crucial experiments, 
which were carried out by Gray and Tulloch on the island of 
Kimmi after my departure. The result was ‘to demonstrate 
conclusively the distinctness of the ‘ wild” trypanosomes 
from T. gambiense. Meanwhile I had written, shortly 
after my return to England, an interim report on my work at 
Entebbe, for the information of the Tropical Diseases Com- 
mittee of the Royal Society. This report was also utilised 
by me in my candidature for the chair of Protozoclogy, which 
I now hold, and a printed copy of it was. sent by me to my 
friend M. Mesnil, of the Pasteur Institute,'who, not being 
aware of its private nature, of which he had not been 
