ii6 seem that we are dealing with T. peconnii, not T. iiainnii.

Certainly fig". 2 shows a trypanbsome more of the fecorum than the nanimi type, and also (if we accept the views of Laveran and MesniP as to T. congolense being a distinct species) than the congolense type. As a matter of fact, so far as the measurements go, they are nearer those given for T . peconim than for T . nanum.

In any case the positive result of animal inoculation puts the matter beyond doubt so far as these two species are concerned. (But see footnote on p. 115.)

If the infection has been derived along the automobile road in Western Mongalla (late Lado Enclave) the vector is in all probability Glossina falpalis, as G. morsitans is not found in this locality, and the only other biting flies in evidence are Haeuiatopota. It is, however, very probable that these bulls were infected before going to Western Mongalla, and that some species of Tabamis, Chrysops, or Stomoxys is the active agent in transmitting this form of animal trypanosomiasis in the Southern Sudan. I have mentioned the donkey from the Moru country.

I kept only one film of this animal's blood, and, as the infection is very small, have not troubled to draw and measure the parasites. The trypanosome, however, is undoubtedly of the same type as that found in the bulls (fig. 3). Again, if we accept Laveran's view, I think it will be admitted that it is very like T . congolense. Considering the history of this trypanosome, it is exceedingly likely that it is T . congolense, but there is, of course, no definite proof so far.

As regards the infected mules at Loka, I took films and fixed them in absolute alcohol, having no osmic acid with me. Later these films were stained with Giemsa. The infection was somewhat sparse, and at a magnification of 2,000 diameters it took a long time to draw even as many as a hundred from different slides.

This, however, was done, and they were measured by Bruce's method, the curve being given in Chart II.

The measurements in respect to length are as follows: 4 Minimum Maximum Average Length in microns ... 105 ... 28 ... 176 Figs. 4 and 5 show the general aspect of the parasites. It will be seen that this trypanosome is of the brucei or gambiense type