124 
KEPOUT OF TRAVELLING PATHOLOGIST AND PKOTOZOOLOGIST 
Herpctomonas 
in Tabanus 
socius 
Work at 
Taufikia, 
White Nile 
W'ork at 
Nasser, on the 
Sobat River 
H(pmocyi>’ 
tid'ium in a 
snake 
A storm on the 
Sobat River 
To return to the dissections of the Seroots which we undertook, Dr. Balfour first found 
in one Tabanus socius large numbers of resting Herpctomonas. It was not till I had dissected 
upwards of tifcy or sixty that I came across an infected fly. I continued the dissections 
of Tabanus socius, after arriving at Taufikia, and found there also only a small percentage of 
flies infected. This was very different from the condition prevailing at Nasser on the Sobat, 
hardly 100 miles distant, where as many as one fly in every three was infected. I remained 
at Taufikia from April 23 to .Tune 16. It was during this time that the wet season set in, and 
much difficulty was occasioned by the leaking of the roof of the laboratory. The leakage was 
effectually stopped by covering the upper deck with ruberoid material sent up from Khartoum. 
At Taufikia I found trypanosomes in donkeys and camels returning from the Bahr-El-Ghazal. 
In the case of the camels only four animals out of seventy-five survived to return to Taufikia, 
after having been in the Bahr-El-Ghazal Province three to four months, and of the survivors one 
died shortly after its arrival and in two of the remaining three I found trypanosomes present. 
Large numbers of animats were examined for blood parasites, with the result that trypano¬ 
somes were found in two species of Varanus, the spiny mouse, several fish and toads, while 
luemogregarines were found in snakes, lizards and toads, and though many birds were examined 
only Ualteridiuvi was present. During my stay at Taufikia, and also on the journey up from 
Khartoum, I commenced the study of the LeiicocytozooJi discovered by Sheffield Neave in 
the blood of guinea fowl, and which is of special interest because of its resemblance to the 
Leucocijtozoon of the little owl, the life-history of which was studied by Schaudinn. 
I left Taufikia on June 16, and reached Nasser on June 19. Nasser, on the banks of the 
Sobat, is a large collection of Nuer and Anuak villages near the borders of Abyssinia. As 
the wet season had set in, the village was surrounded by large stretches of swamp, and 
accordingly mosquitoes w'ere very numerous. Examination of the blood of the natives 
revealed a widespread malarial infection. Ten beads were offered to anyone who submitted 
to having his blood examined, and though at first this was not a sufficient attraction, later on 
it overcame suspicion and brought large numbers to the floating laboratory. Several hundreds 
of mosquitoes were dissected, and though malaria was so prevalent, not a single example of 
plasmodium-infeeted mosquito was encountered. In one, Myzomyia nili, Herpctomonas was 
discovered, and in one Tceniorhynrhus tenax, encysted nematodes, probably filariae, were 
found among the thoracic muscles. In TabanidcB, Herpctomonas occurred in Tabanus socius 
as well as in other species. The occurrence of these flagellates in the Tabanidce is of interest 
in connection with the trypanosomiasis in those districts of the Sudan not infested with Glossince. 
On the Sobat, cattle are infected with Trypanosoma nanum, and as here no Glossina occurs, it is 
possible that the Tabanidce are concerned in its transmission. However, it must be remembered 
that Tabanidm are found to be infected in countries where no cattle trypanosomes occur. 
At Nasser, in one of the black spitting cobras, an interesting parasite, w'hich had hitherto 
only been found in two other hosts, was discovered. This is a pigmented intra-corpuscular 
parasite named Hceviocystidium, which occurs in an Indian river tortoise and lizard, and also 
in a South African tortoise. In the same snake a trypanosome was discovered. Toads at 
Nasser were generally infected with filaria. 
During the whole of my stay at Nasser the weather was very bad, with frequent thunder¬ 
storms. The country round was swampy, so that it was impossible to travel much in the 
neighbourhood, and on many days I was quite unable to leave the barge. In one thunder¬ 
storm the floating laboratory only just escaped what might have been a serious disaster. The 
wind rose with tropical suddenness, and carried away the barge from its moorings and drove 
it for about a quarter of a mile up the river against the stream, which was then flowing at 
three or four miles an hour. The floating laboratory fortunately proved itself equal to the 
test, or it would have sunk with all its equipment to the bottom of the Sobat. 
