18 



Clapier (— ). Index palustre chez les Indigenes de la Commune 

 de Bangui (Afrique Equatoriale Frd^ncaXse).— Bull. Soc. Path. 

 Exot, Paris, xii, no. 8, 8th October 1919, pp. 538-549. 



The geographical and cUmatic conditions, the population and 

 vegetation of Bangi, the capital of the French colony of Ubangi- 

 Shari in French Equatorial Africa, are discussed with reference to 

 malarial prevalence. Mosquitos are not extremely abundant m 

 the region, and are becoming less numerous with better conditions 

 of drainage and clearing of the land. During the dry season of 1918, 

 while a few Culicines were found, including species of Culex, Stegomifia 

 and Mansonioides, Anophelines were much rarer and more difficult to 

 find. In seasons of heavy rains the breeding places increase and 

 the number of Anopheles is proportionately larger, the malarial 

 incidence increasing in consequence. Permanent carriers of the 

 virus are very numerous at Bangi and are widely distributed through- 

 out the region. The average malarial index of the year was found 

 to be 78 per cent. It is noticeable that in the villages similarly 

 situated in valleys beside rivers that overflow their banks, the malarial 

 incidence is practically the same throughout and is much higher 

 than the average. The lowest percentage, 53 per cent., was recorded 

 for a village situated 623 metres above the valley on a vast plateau 

 that is provided with natural water. It has already been proposed to 

 utihse this spot for some useful estabhshment under the Health 

 Service. 



Tables are given showing the malarial index and the splenic index 

 for children. The favourable action of atoxyl upon malaria is con- 

 firmed by treatment in this region. The variations of the index 

 according to the season is not great, being apparently never more 

 than 15 per cent. The types of malaria parasite recorded are 

 Phsmodium praecox {falciparum) 42*5 per cent., P. vivax 491 per cent., 

 and P. malariae 8-4 per cent. No defi.nite predommance of any 

 form can be indicated for any particular place or season. The con- 

 clusion drawn from these observations is that most of the regions 

 of Equatorial Africa are almost uniformly malarial. 



LiGNiERES (J.). Piroplasmes, Anaplasmes et Grains chromatiques. — 



Bull. Soc. Path. Exot., Paris, xii, no. 8, 8th October 1919, pp. 

 558-566. 



This paper discusses the tendency to confusion between the parasitic 

 organisms Anaplasma, Piroplasma, and certain chromatic grains 

 recovered from cases of acute anaemia, either natural or experimentally 

 produced. Experiments by the author in Argentina upon Anaplasma 

 argmtinum coniirm those of Theiler and indicate that Anaplasma is 

 not merely a phase in the evolution of Piroplasma, but is quite a 

 distinct organism. Immunity transmitted by the former is negative 

 for the latter and vice-versa. Moreover, contrary to the author's 

 early beUef [R.A.E., B, ii, 172], it is now recognised that the tick, 

 Margaropus mieroplus, which readily transmits piroplasmosis in 

 Argentina, does not usually transmit anaplasmosis. This is an 

 obscure point, but the agency of another tick of the genus Amblyomma 

 is suspected in this connection. 



