136 
KEPORT OF TRAVELLING PATHOLOGIST AND PEOTOZOOLOGIST 
This camel 
trypanosome 
probably 
T, pecaudi 
'I'he disease in 
donkeys and 
mules 
The 
trypanosome 
concerned 
probably 
T. pecaitdi 
Tsetse flies at 
Wan 
and that this trypanosome is in reality Trypanosoma pccaudi which occurs in other animals in 
the same district.^ 
Donkeys and ^lules 
In donkeys and mules the trypanosome described hy Dr. Balfour in the Second Eeport 
of the Wellcome Eesearch Laboratories was encountered on several occasions. I first saw it in 
a donkey at Taufikia which had come down from the Bahr-Bl-Ghazal Province. By inoculation 
of rats I was able to keep this strain of trypanosomes during the whole time J was in the 
Sudan. As a rule the animals became infected in five or six days and lived about one month 
after infection. On no occasion did I find a rat refractory to inoculation. Through all these 
passages the trypanosomes retained their original form, the three main types which have been 
mentioned above as occurring in the case of camels seen at Taufikia being always evident. 
The majority of the trypanosomes are of the two types described by Laveran, but in addition 
there occurs also, but in much smaller numbers, a short form very much like T. nanmn. 
This form may be no more than 12/i in total length, and has no free flagellum or one that is very 
short, is indistinguishable from the forms of T. nanum, and corresponds with the “ tadpole ” 
forms of T. dimorphon described by Dutton and Todd and others. 
The three forms that I have met with are : 
1. Long forms resembling T. Evansi. 
2. Forms without free flagella and measuring about 14p. Nucleus may be central or 
anywhere between this point and close up to the micronucleus. Very commonly a vacuole is 
seen lying against the micronucleus. The membrane is very wide, the total width of body, 
including the membrane, from 4 to 4’5/(. Body may be very granular between the nucleus 
and flagellar extremity. 
3. Forms with no free flagella or ones that are very short, nucleus centrally placed, 
undulating membrane little developed. Total length about 12 to 14/i. Very closely 
resembling Trypanosoma nanum. 
These three forms have been mentioned in Dr. Balfour’s account of this trypanosome. 
They are figured in Plate I., figs. 1 and 3. In his account in the last volume of the Eeports 
Dr. Balfour inclined to the view that this trypanosome was T. dimorphon of Dutton and Todd, 
but he is now of the opinion that it is more probably T. pecaudi. This latter view is in all 
jirobahility the correct one. 
The distribution of Glossina in and around Wau is of interest. In Wan itself I 
did not encounter Glossina morsitans, but Glossina palpalis occurred regularly in small 
numbers. On the Wau river, about five miles from Wau, Glossina morsitans first appeared. 
Animals remaining in Wau did not become infected with trypanosomes, hut after a short 
trip outside Wau they frequently became infected. A mule which had remained perfectly 
healthy in Wau for a year or more was taken across the Wau Eiver for two or three days and 
there contracted trypanosomiasis, from which it died a monih later. This animal, though it 
was stabled with other mules and donkeys, did not become a centre for a general infection- 
This may have been due to the absence of Glossina morsitans in Wau, and that Glossina palpalis 
was unable to transmit this trypanosome or was present in too small numbers. Experiments 
with Glossina palpalis and infected rats gave only negative results, even when the fly was fed 
on a healthy rat directly after feeding on one whose blood was swarming with trypanosomes. 
' This trypanosome resembles in many respects T. dimorphon of Dutton anti Todd and also T. pecaudi. 
The identity of this trypanosome with either of these is discussed by Dr. Balfour in this volume of the Report, 
with the result that he decides for the T. pecaudi view. In my account I shall speak of his trypanosome 
therefore as T. pecaudi. 
