Ill 



Sir Ronald Ross expressed the hope that further investigations 

 will be made as to the correctness of the author's hypothesis that 

 there are two strains of benign tertian parasites in England. 



BousFTELD (L.). Malaria, with reference to (1) the Danger of imported 

 Anopheline Insects, (2) an unusual Breeding Ground. — Trans. Soc. 

 Trop. Med. Hyg., London, xii, no. 3, 17th January 1919, pp. 52- 

 58, 2 figs. 



Besides the natural sources of infection from malaria in Khartoum, 

 there is a large traffic in steamers, native boats and trains coming 

 from highly malarious districts. Since preventive measures have 

 been adopted the town has been very free from infection until recent 

 years. This is accounted for by the increased native boat traffic 

 to supply wood owing to the shortage of coal. The boats travel 

 slowly down the Nile from malarious districts and are moored to the 

 banks at night ; mosquitos come on board them and having fed on 

 the native crew, shelter in the cargo and remain undisturbed until it 

 is unloaded. As the Anophelines found on board are usually females, it 

 is believed that human blood is the attraction ; they very seldom breed 

 on board, whereas Cidex and Stegomyia frequently do so. Mosquitos 

 have been found in houses near the river bank that had been free 

 from them for months. 



Details are given of the anti-malarial measures adopted in the 

 district. 



Anopheles {Pyretophorus) coskdis, Culex fatigans and Stegomyia 

 fasciata breed locally, whereas Anopheles {Cellia) pharoensis and an 

 unidentified species of Cidex have been found in houses near the river 

 banks and trains, but do not breed locally. When the Nile receded 

 in 1917, after the inundation around Khartoum, a mud fiat was 

 formed by the deposited silt in which Anopheline larvae, probably 

 those of A. costalis, were found, 



Hornby (H. V.). The Trypanosomes found in Domestic Mammals in 

 South Central Africa. — Vet. Jl., London, kxv, no. 4, April 1919, 

 pp. 128-138. 



The following is the author's summary of this paper : The common 

 trypanosomes found in domestic mammals in South Central Africa are 

 three in number viz : — Trypanosoma brvcei, T. congolense and T. vivax. 

 They are readily distinguishable by their morphological characters. 

 T. bntcei is very fatal to equines, smaller ruminants and dogs, but 

 is almost non-pathogenic for cattle. T. congolense is the commonest 

 cause of trypanosomiasis of cattle, but it is also pathogenic for 

 other domestic mammals. T. vivax resembles T. congolense in the 

 forms of disease it causes in stock. Dogs are generally immune to 

 its ill-effects. 



The distribution of these parasites is coincident with that of tsetse- 

 flies. Different strains of the same species of trypanosome vary 

 greatly in their range of virulence. Individuals and races of the same 

 species of domestic animals vary greatly in the resistance they offer 

 to infection. The presence in the blood of one species of parasite 

 appears to inhibit the development of another. 



(C573) a2 



