345 
The patient stated that he had never been near either Lake 
Tanganyika, Lake Mweru or the Luapula River, which are known 
to be infested by Glossina palpalis. He thought, himself, that he 
contracted trypanosomiasis while travelling along the Luangwa 
River, between Mzaza and Feira. The Luangwa Valley is heavily 
infested with Glossina morsitans , but Glossina palpalis has not yet 
been found along the course of this river. 
Dr. Bagshawe’s article, already noted, on * The Transmission in 
nature of Trypanosoma gambiense* should be consulted as to cases 
of sleeping sickness contracted in areas infested by Glossina 
morsitans. 
We may note that the case of W. A. has been studied by R. Ross 
and D. Thomson,* who have found a regular periodical increase 
in the numbers of the trypanosomes in the peripheral blood of the 
patient from day to day. 
It is also of interest to record that the Rhodesian strain of 
trypanosome from W.A. is somewhat more virulent to rats and 
guinea-pigs than the old laboratory strain of T. gambiense , a fact 
already confirmed by other workers in the laboratory. Further, 
this Rhodesian trypanosome is resistant to atoxyl. 
MORPHOLOGICAL FEATURES 
It may be stated at once that the peculiarity of this Rhodesian 
trypanosome is that among the stout or stumpy forms some have 
the nucleus at the posterior (non-flagellar) end. 
As will be seen from the accompanying figures (Plate XXII, figs. 
--I0), the position of this ‘ posterior ’ nucleus varies. Starting from 
the stumpy forms in which the nucleus is in the middle (fig. 0. we 
have all transitions (figs. 2-8) up to that in which the nucleus is 
actually terminal (fig. 9) and posterior to the blepharoplast 
'kinetonucleus). 
We may meet here any objections that may be raised that the 
trypanosomes with posterior nucleus are due to distortion, dried 
hlins being used, because: — 
L We have never found them, though persistently looked for, 
in films from the same animals infected with the old laboratory 
* Roy. Soc. Proc., B., 1910. Vol. LXXXII, pp. 4"--Kv 
