27 



of the usual carrier, Dermacentor vcnustns, are dealt with. The author 

 beheves that hereditary transmission in many generations of this tick 

 helps to maintain the disease without fresh introductions from a 

 mammaUan source. The existence of local foci of infection would 

 indicate that this is an important factor in maintaining the virus 

 in nature. Ticks do not travel great distances except on the host, 

 and only the larger host animals have a wide range. These and other 

 factors must tend to retard the extension of the areas occupied by 

 infected ticks. 



The author treats the causative organism as in an intermediate 

 position between bacteria and protozoa, and proposes the name 

 Dermaceniroxenus rickettsi for it. 



There is a strong clinical resemblance between this disease, typhus 

 and tsutsugamushi disease. 



MANS0N-B.4HR (P.). Experiences of Malaria in the Egyptian Expe- 

 ditionary Force. — Lancet, London, no. 5028, 10th January 1920, 

 pp. 79-85, 6 figs., 1 map. 



The observations here recorded are divided into two portions, the 

 first concerning Egypt and the Suez Canal Zone, and the second 

 Palestine. 



During August and September 1916, there was a relative scarcity 

 of AnopheHnes in the southern sector of the Canal Zone. The most 

 abundant species were Anopheles {Cellia) pharaoensis, A turkhudi and 

 A. maiiritianus. The two former bred in the borrow-pits near the 

 Sweet Water Canal and in the seepage water from the subsidiary 

 channels, but not in the canal itself, owing to the large numbers 

 of surface-feeding fish. A. mauritianns bred in highly saline water 

 in the vicinity of the Bitter Lakes. A. pharaoensis is a recognised 

 carrier of the parasite of benign tertian, while A. maitritianus has 

 never been proved to be a vector. Transmission by A. titrkhndi of 

 the maUgnant parasite has been proved experimentally, A. pharaoensis 

 being but a casual transmitter of this disease. 



In the Fayoum, A. pharaoensis was the most abvmdant species in the 

 Western Oases, and a number of subacute cases of malaria occurred 

 in Januarv 1917, ten days after the arrival of the troops. Among the 

 points noted are the fact that maUgnant tertian malaria could be 

 transmitted during the winter, when the surface temperature of the 

 sand at night was as low as 1° C. [34° F.], and the high rate of infection 

 amongst the native population, the children under 14 having a splenic 

 index of 96-4 per cent. The mosquito concerned was either A. siiper- 

 pictiis {palestinensis) or perhaps a variety of A. turkhudi, of which 

 large numbers were breeding in the warm springs (temperature 80° ¥.) 

 watering the Dahkla oasis throughout the winter. 



In Palestine, malaria, particularly of the mahgnant variety, was apt 

 to assume epidemic form during the autumn months, especially mid- 

 October. The cases that occurred were such as to warrant the suspicion 

 that the infection had been locally acquired during the winter months. 

 The Anophelines infected during the previous autumn appeared to be 

 capable of conveying the infection during the winter to troops quartered 

 in native houses. Females of A . bifnrcatus were proved to be capable 

 of ovipositing in winter, the eggs yielding active larvae in sheltered 

 places, such as deep wells. On the seaboard and the plain of Sharon, 

 the benign variety of malaria predominated, while east of Jerusalem the 

 (5610) c 2 



