160 E. A. MINCHIN. 
December, 1905. Some of my results have already appeared 
in the form of preliminary reports; but with regard to some 
few points further study necessitates revision or correction of 
statements previously made. In my eight months in Uganda 
I accumulated a great deal of material which it has required 
much time and labour to work out. The study of this 
material has occupied the time left from other duties since 
my return from Uganda, and may now be considered complete. 
The commission with which I went to Uganda was to study 
the life-cycle of Trypanosoma gambiense in its relation 
to the local species of tsetse-fly, Glossina palpalis. In 
view of the well-known life-cycle of the malarial parasite, 
as well as of the remarkable development described by 
Schaudinn (40), for the trypanosomes of the little owl 
(Athene noctua), it seemed probable that a study of the 
sleeping sickness trypanosome in its passage through the 
tsetse-fly would reveal an interesting developmental cycle. 
Unfortunately, these expectations have not been fulfilled, 
and, so far as the development of Trypanosoma gambiense 
is concerned, my investigations have been barren of results, 
and have yielded conclusions for the most part of a negative 
character. Incidentally, however, I have made some observa- 
tions which are, perhaps, not without interest, on another 
species of trypanosome occurring in the fly, and a record of 
my work and its results may be of some use if only as a guide | 
to future investigators in this field to enable them to avoid 
my failure. 
In the exposition of the numerous and complicated data 
furnished by an investigation of this kind, it is difficult to 
steer clear between, on the one hand, too much subjective 
interpretation, which may become misleading; and, on the 
other hand, excessive elaboration of detail, which becomes 
tedious and difficult to follow. I propose, therefore, to 
divide this memoir into two chief parts: I shall first set 
forth the development, so far as I have observed it, of the 
two species of trypanosomes ina connected manner, and shall 
discuss the general question of the transmission of trypano- 
