122 



As regards the distribution of malaria in space, centres of endemic 

 malaria can be recognised that are more circumscribed than the cor- 

 responding Anopheline areas. These are the ancient foci of malaria, 

 now latent, and are a standing danger to the country, since the intro- 

 duction of new reservoirs of the malarial parasite is all that is needed 

 to restore their endemicity. 



Locally the length of the cycle varies ; in ancient Greece it covered 

 many years ; at the present time in Macedonia it is three years. In 

 1916 malaria appeared late ; AnopheUnes were abundant, appearing 

 at the end of April and in May, and malaria died out late in the year, 

 there being a slight recrudescence in the middle of November due to 

 an Anopheline outbreak in October, owing to the coolness of the autumn. 

 In 1917, both Anophelines and malaria appeared late, the small 

 numbers of the former being correlated with a mild outbreak of the 

 latter. 



Meniaud (J.). Les Chevaux du Haut-S6n6gal et Niger. [The Horses 

 of Upper Senegal and Niger.] — La Vie Agric. et Rur., Paris, viii, 

 no. U, 6th April 1918, pp. 241-246. 



Of the chief insect-borne diseases attacking horses in the Upper 

 Senegal and Niger regions such as trypanosomiasis and piroplasmosis, 

 the former is the most deadly, decimating whole regions by the end 

 of winter, and each year causing the loss of several hundreds of horses. 



Three species of tsetse-fly found in W. Africa are able to convey 

 infection with Trypanosoma pecaudi in varying degrees. Glossina 

 longipalpis does this to a greater extent than G. tachinoides, while 

 G. palpalis scarcely ever transmits this trypanosome. 



The dominant species of tsetse in Upper Senegal is G. palpalis, 

 the examples of G. tachinoides that are met with being everywhere 

 mixed with it. The former species can transmit the largest number 

 of trypanosomes, namely sleeping sickness, caused by T. gambiense ; 

 souma, a disease characterised by a nasal discharge, caused by T. cazal- 

 boui ; and baleri, caused by T. pecaudi, as well as T. dimorphon, which is 

 however only rarely met with in Senegal, though it occurs in Guinea 

 and the Ivory Coast. Tsetse-flies do not appear to occur north of 

 the 14th parallel of S. latitude. They are not however the only 

 vectors of animal trypanosomiasis, as Stomoxys and Tabanids are 

 able to carry the disease from a sick to a healthy animal, and horses 

 situated far from a tsetse area may thus become infected. 



CuRWEN (H.). Report on the Public Health Division for the Year 1916. 



^Zanzibar Protectorate Ann. Rept. Pub. Health Dept. for 1916, 

 Zanzibar, 1917, pp. 1-25. 



The mosquito conditions existing in Zanzibar are discussed and 

 have been dealt with previously [see this Review, Ser. B, vi, p. 46 and 

 v, p. 147]. The chief mosquito-borne diseases are filariasis, which 

 is said to occur in some 30 per cent, of the native population, elephan- 

 tiasis and filarial lymphangitis, which have increased within the town 

 in recent years, and malaria. While no present records are any guide 

 to the prevalence of malaria in the Protectorate, owing to the large 

 number of cases treated by native doctors, there is a regular fever 



