42 



Murray (W. A.). Note on Relation between Tsetse-fly [Glossina 

 morsitans) and Game in the Proclaimed Area, Nyasaland. — Trans. 

 R. Soc. Trap. Med. & Hvg., London, xv, no. 4, 20th October 

 1921, pp. 118-121, 1 map. " 



Tsetse-flies are widely distributed over Nyasaland, but are chiefly 

 found in the narrow forested belt on the western shores of Lake Nyasa, 

 Glossina morsitans being the most important species. 



In this area in 1896, rinderpest almost exterminated the cattle and 

 game, and the flies were reduced in numbers to a corresponding extent. 

 After 1904, the game increased and scattered over the greater part of 

 the area, and the fly spread concurrently, with the result that many 

 domestic animals died of trypanosomiasis. Trypanosoma pecontm was 

 the organism concerned in all cases examined by the author. These 

 observations only apply to the low-lying parts of the area ; above 

 an altitude of 3,000 feet, fly was rarely found, although game was 

 abundant. 



Murray (W. A.). History of the Introduction and Spread of Human 

 Trypanosomiasis (Sleeping Sickness) in British Nyasaland in 1908 

 and following Years. — Trans. R. Soc. Trop. Med. c- Hvi^., 

 London, xv, no. 4, 20th October 1921, pp. 121-128, 1 m^p. 



A historical survey of sleeping sickness in Nyasaland is reviewed as 

 evidence in support of the author's opinion that human trypanoso- 

 miasis did not exist there prior to 1907-08, but was introduced at that 

 time from Lake Tanganyika or North-east Rhodesia or both. 



It appears that Trypanosoma rhodesiense was most virulent and 

 spread very rapidly immediately after its first introduction, but has 

 since been much reduced after many passages through the three hosts 

 concerned — man, game and fly. The author assumes that its original 

 source was T. gambiense from the north, and by some unknown tran- 

 sition the change of vector from Glossina palpalis to G. morsitans has 

 resulted in a different strain of trypanosomiasis, causing a more 

 virulent form of disease. 



CoNNAL (A.) & CoNNAL (S. L. M.). A Preliminary Note on the Develop- 

 ment of Loa loa (Guyot) in Chrysops silacca (Austen). — Trans . 

 R. Soc. Trop. Med. & Hvg., London, xv, no. 4, 20th October 

 1921, pp. 131-134. 



Investigations made near Lagos from May to July 1921, as to the 

 possibility of Chrysops being the carrier of Filaria [Loa) loa are here 

 described. Of the five natives selected as the source of the infecting 

 feed, three were chosen because the number of embryos in their blood 

 was high, and the other two because the number was small. 



Within six hours of the infecting feed the majority of the embryos 

 reached the abdominal muscles of the fly, the remainder proceeding to 

 the thorax and head. In a heavy infection, young filariae ma}' be 

 found in these situations in 24 hours. The embryos do not all develop 

 with equal rapidity. In 5-6 days, young filariae are seen coiled up in 

 the muscles. No stages where motion had entirely ceased were observed 

 as is described in the case of Filaria bancrofti. The final stage is reached 

 in 10-12 days, when the filariae begin to travel towards the head and 

 accumulate at the root of the proboscis and in the labium. They 

 gain exit by the labella. 



