274 R. B. WOOSNAM — SEARCH FOR GLOSSINA ON THE AMALA 



In May 1911, five mules were taken to the lower store and used on a hunting 

 expedition down the river on the east side only. It is noted in Mr. Judd's diary 

 that several kinds of biting flies were very troublesome, but no tsetse-fiies were 

 seen, and Mr. Judd is thoroughly familiar with these insects. However, one of 

 these mules became ill, and upon its return to Nairobi in June it was examined 

 at the Government Laboratory, and found to be infected with trypanosomes and 

 died later. 



In June and July, two teams of ten mules were doing transport work between 

 Nairobi and the lower store, using a road which did not approach the river until 

 it reached the store. It is said that none of these animals crossed the river, but 

 they drank daily at a ford near the store where the river is not more than 

 30 yards wide. Five of these mules became ill and died, but they were not 

 examined for trypanosomiasis. They used to remain four or five days at the 

 store before returning to Nairobi. After this, mules were no longer used and a 

 team of 18 oxen was tried under similar circumstances. Seven of them became 

 ill and five died ; but they were not examined for trypanosomiasis. They were 

 said never to have crossed the river, but drank at the ford daily. 



In November 1912, Judd moved his store some 15 miles higher up the river, 

 on account of having lost so many animals from suspected trypanosomiasis. 



All this evidence tends to show that the tsetse-fly in the area under discussion 

 is either confined to the west bank of the river, or to that bank and the east 

 bank in the immediate vicinity of the river, and this theory is strengthened and 

 explained when the physical features and conditions of vegetation in this area 

 are taken into consideration, which I shall describe later. 



When I Avas obliged to leave this district, I told the old Masai who had acted 

 as guide that if he could catch some more tsetse-flies and would bring them up to 

 the Government post he would receive five rupees and I left him a box in which 

 to put them. I am glad to say that about ten days later he brought in three 

 flies which were sent in to Mr. Anderson according to my instructions. They 

 proved to be Glossina, of the same species as the one first obtained, and they 

 were sent by Mr. Anderson at once to Mr. Guy Marshall in London. 



The old Masai, Ol-botor-ol-joni, who undoubtedly knows a tsetse-fly at once 

 by sight and who also knows a good deal about them and their distribution, told 

 me that there was another species of tsetse-fly to be found in this area, which 

 was much smaller and of a lighter brown colour, but it was not so numerous 

 and was very shy. I shall endeavour to obtain this fly, which of course may not 

 be a Glossina. However, I showed the old man several Haematopota and 

 StomoxyS) which he said were not at all like it. 



When I arrived first at Ol-botor-ol-joni's village I found that he was said to 

 be ill and he was unable to accompany me as guide on this account. As he had 

 evidently spent a good deal of his time in the fly-areas I thought it worth while 

 taking some smears of his blood. I had some difficulty in persuading him to 

 submit to this, but eventually he allowed me to draw a little blood from his 

 finger. I examined this while fresh under a cover slip and also in stained 

 preparations, but could find no trypanosomes, after spending two hours over each 

 of the stained slides. He said he had been ill for about ten months, lie 

 complained of pain in his head and stomach and back. He showed marked 



