198 



Sambon (L. W.). Tropical and Sub-Tropical Diseases. — United 

 Empire, London, N.S., xi, nos. 8 & 9, August & September 1920, 

 pp. 420-431 & 493-503. 



This paper read at a meeting of the Royal Colonial Institute reviews 

 the history of many tropical and sub-tropical diseases, with special 

 reference to insect transmission. Many previous authors are quoted, 

 and their work is discussed. 



Duncan (M.). On Acari from the Lungs of Macacus rhesus. — Jl. R. 

 Microsc. Soc, London, 1920, part 2, June 1920, pp. 163-168, 

 1 plate, 2 figs. [Received 7th September 1920.] 



Attention is drawn to the occurrence of an Acarid, Pneumonyssus 

 foxi, in the lungs of a monkey {Macacus rhesus). The whole life-cycle 

 is apparently passed in this environment, but how the mite originally 

 gains entrance to the lungs of the host has not yet been definitely 

 ascertained. [See also R.A.E., B, iv, 40.] 



Sinclair (J. M.). Southern Rhodesia : Report of the Chief Veterinary 

 Surgeon for the Year 1919. — Salisbury, 1920, pp. 1-8. [Received 

 7th September 1920.] 



The number of fresh outbreaks of African coast fever in Rhodesia 

 during 1919 was eight, and the mortality 798 head. The heavy mor- 

 tality attending the outbreaks in two localities in which dipping had 

 been constantly practised led to a good deal of criticism of the system. 

 In one of these cases the mortality during the first four months was 

 437 head as against only nine during the next four. The degree of 

 infection to begin with was one of the heaviest that has ever had to 

 be dealt with, and but for dipping, less than 10 per cent, would have 

 survived three months. In the second case over 50 cattle actually 

 suffering from the disease were deposited by rail on three farms where 

 tick infestation was at a minimum as the result of regular dipping 

 over a considerable period. The results were disappointing, as over 

 266 head out of 615 contracted the disease and died, or were destroyed. 

 The mortality was heaviest among the worldng oxen, and it has been 

 suggested that this was due to the rapid ehmination of arsenic from 

 the skin as the result of the constant daily exertions. There is probably 

 something in this view, but the high mortality generally was due to 

 the fact that the imported infected cattle were heavily tick-infested 

 on arrival, and apparently were not dipped until a week later. In 

 connection with this outbreak it has been alleged that the methods 

 were at fault in that dressing of the ears and tails was not carried 

 out. These processes have not been insisted on in cases where 

 dipping has been regularly practised, and there is nothing to show 

 that the subsequent mortahty has consequently been increased. 

 Records show that, whatever the methods of dipping, etc., the period 

 required to eradicate infection depends entirely on the degree of 

 infection in existence to begin with. 



During 1919, 229 dipping tanks were constructed, making a total 

 of 1,583, but many are still required for the proper carrying out of 

 the Cattle Cleansing Ordinance (1918). 



