428 Degeneration of T. gambiense 
filament drying down on to the tropho-nucleus and thus appearing to 
pass through it. 
The axial filament does not seem to be constantly present and is 
usually very difficult to trace along its whole length, but from the ar¬ 
rangement of the granules in either one or two longitudinal rows, it 
seems possible that it may be present even when not visible. During 
certain kinds of degeneration this structure may become densely 
chromatic and is then very conspicuous (figs. 13—16), but as a rule it 
is almost achromatic. 
With the exception of one at each end of the axial filament, it is 
not usual to find granules occurring in the cytoplasm of the trypanosomes 
before treatment. At times, however, a few granules of volutinose may 
be extruded from the tropho-nucleus, but they rapidly dissolve in the 
cytoplasm. They probably represent degeneration products of the 
chromatin which have been cast out by the nucleus, especially when 
under abnormal conditions. 
Certain chromatic granules are also given off from the kineto- 
nucleus and pass forward towards the tropho-nucleus (figs. 2, 6). The 
nature of these granules is uncertain, but they are unquestionably 
different from the volutinose granules of the tropho-nucleus, as they 
stain with iron haematoxylin and are often present before treatment. 
(6) The trypanosomes after treatment with arsenophenylglydn. 
Shortly after the injection the most noticeable alteration in the 
appearance of the trypanosomes is the retraction of the posterior end, 
so that the kineto-nucleus appears at the extremity of the body, and in 
some cases even outside it (figs. 29, 34). This phenomenon has been 
described by Nuttall (1910) in the case of T. hrucei after treatment 
with arsenophenylglycin, and is most clearly seen in dry films. 
A differential count of the trypanosomes before and after treatment 
brought out the fact that whereas before the injection only 22 pos¬ 
sessed blunt posterior extremities, one hour after 96 “/o shewed this 
rounded appearance. 
The number of parasites containing granules, especially in the 
anterior region of the body, increases to nearly 100 “/o within two hours 
after treatment, their number gradually increasing until the parasite 
finally breaks up into fragments. As mentioned above, it is possible to 
^ The presence of the “ stumpy forms ” of T. gamhiense makes this percentage higher 
than in the case of T. brucei. 
