TEYl'ANOSOMIASIS IN THE ANGLO-EGYPTIAN SUDAN 149 



present and full of chromatin grannies. Some seen undergoing longitudinal division. 

 Animal looks ill and emaciated, but weight was 1'2 kilos. Treatment with chrysoidine begun 

 so considered later (p. 160). 



Exp. 50, 51 and 52 have not been concluded at the time of writing and so need 

 not be considered. 



I append tables giving details of these inoculation experiments, so that the results 

 obtained can be readily noted (p. 128 et seq.). 



Having described these, we are in a better position to discuss the identity of the 

 trypanosome or trypanosomes in question. It appears to be always a matter of considerable 

 difficulty to come to a definite decision on such a point, and indeed it may be impossible 

 without the aid of cultivation and immunisation experiments. Koch* has recently raised 

 the question as to whether it will not be possible in certain cases, and especially in the 

 pathogenetic trypanosomes of mammals, to decide the species by a study of the developmental 

 forms in the (rlussinn. The question at issue, it will be remembered, is whether we are 

 dealing with 'J\ diinorij/timi or with an infection by two different species of trypanosomes, 

 one of these being presumably 7'. Evansl. For purposes of comparison I would direct 

 attention to the standard treatise on Trypanosomiasis by Laveran and Mesnil, which deals 

 fully both with T. diiJtorj)hiim and T. Uvansi; to the work of Dutton and Todd, on 

 the former parasite, found in horses in Senegambia, and to the very full report of 

 Musgrave and Clegg, which refers especially to Surra in the Philippine Islands. 



Dealing first with the morphological aspects of ?'. iliinor/ihiiiii as described by Resemblances 

 Dutton and Todd, who discovered it, I think it will be apparent to anyone who compares 

 their photomicrographs of the horse trypanosome of the Gambia with those of the mule 

 trypanosomes of the Sudan, Fig. 69, that they are extremely alike. This applies at least 

 to their Figs. 2 and 3, on Plate 1. There, long forms exactly similar to those shown in 

 Fig. 69 appear, while their so-called " stumpy " parasites correspond closely to what I have 

 described as short forms. 



Again comparing their long forms in the coloured plate with those in my stained 

 specimen, I find a great similarity in structure. 



On reading the descriptions of their long and " stumpy " forms, one finds their account 

 of the former agrees with that I have given of the long forms in mules with one 

 possible exception. 



They state that these forms are most numerous in the blood of an infected animal a few 

 days before its death. 



In my untreated cases they occurred early in the infection, persisted throughout the 

 disease and were not specially numerous ante-mortem. 



Taking next their " stumpy " forms. These appear to answer fairly closely to my 

 short forms — at least, as seen in experimental animals. In the original mule's blood I never 

 found them so broad as they describe. They note that the stumpy forms survive for a 

 longer time in fresh preparations than the long forms. I have found this true of my short 

 forms so far as cover-glass preparations go. Sometimes it is very difficult to say if a 

 trypanosome is really a short form or a long form which has become much broader than usual 

 prior to division, and in which the flagellum has not stained well or is not well developed. 

 This leads to confusion, and possibly may account in some measure for the intermediate 



to 



'r. diniorphum 



* Sitzungber d. Kaiser pr. Akad. d. Wiss., Berlin, Nov. 23nl, 1905, p. 958-962. 



