RESEARCH IN SIERRA LEONE. 187 



Trypanosomiasis of Stock- 



This disease has been referred to in several parts of the report, but more 

 especially on p. 164 with regard to Kamatoto and Yiraia Sokurella. 

 There can be no doubt that this disease is very prevalent, but so far as one can 

 gather it does not seem to account for anything like a heavy mortality, if we 

 exclude the two exceptional cases mentioned. 



In the Koinadugu district, cattle form a large source of the wealth of the 

 natives, especially the Limbas, and an examination of the map shows that 

 Glossina palpalis and G. longipalpis are very abundantly distributed in this 

 region. The Timanis are great cattle breeders and reference has already been 

 made to the large cattle towns, e.g., Rowerri and Resorse, in the Karene District. 

 In fact, it may be said that, with few exceptions, cattle are to be found all over the 

 Protectorate. In most places they look exceedingly healthy (Plate XVIII, fig. 1). 



It is very difficult to say how far immunity may have been acquired, but one 

 thing is certain, namely that, despite all the conditions for infection being present, 

 the rate of mortality is low. 



On the other hand, Sierra Leone has a bad reputation for horses. Of seven 

 examined between Port Lokko and Kaballa, near the Great Skarsies River, 

 trypanosomes were found in the blood of three. The infection was very scanty 

 and it is very difficult to say what the species was, but morphologically they 

 appeared to belong to Trypanosoma evansi. 



Some years ago, several donkeys were brought from the Gambia to Sierra 

 Leone and quartered at Port Lokko — perhaps the most unfortunate selection of 

 a camp that could have been made. In a short time nearly all died, but, so far 

 as I could find out, no data or history of the cases is available for any definite 

 conclusions to be drawn as to the cause of death. When I was at Port Lokko 

 in 1912, I saw a foal belonging to one of these donkeys, and it looked in perfect 

 condition and showed no signs of trypanosomiasis. This experiment is well worth 

 repeating because, so far as one can see, the conditions are quite as favourable for 

 donkeys in Sierra Leone as in the Gambia. The original experiment should be 

 disregarded, as it proves absolutely nothing. If such an experiment be under- 

 taken, it must be done under proper supervision and a detailed history, both 

 clinical and microscopic, of every case should be kept. 



The two epidemics referred to on p. 164 call for attention at this point. 

 The history of these as given by the natives is certainly suggestive of trypan- 

 osomiasis, and one is immediately confronted by the question of the source of 

 infection. I have nothing further to add to what has already been said, but I 

 would once more point out the desirability of a systematic examination of the 

 blood of all game, large and small. The solution of this problem and the 

 introduction of animal transport to Sierra Leone would mean a material increase 

 in the prosperity of the Colony. 



VII. The Genus Glossina. 



This, genus is represented in Sierra Leone by five species, namely : — G. 

 palpalis, G.fusca, G. longipalpis, G. pallicera, and G. nigrofusca. 



Of these, however, only the first three require to be taken into account in a 

 discussion on distribution, as our knowledge of G. pallicera and G. nigrofusca is 

 based on a single record in each case. 



