every infected native herd there was a history of exchanging cattle 

 with, or temporary hiring to, traders or transport riders. In 1908, 

 a cattle-owner came into the district with sick cattle and lost most of 

 them in three years from trypanosomiasis. With his advent, the 

 disease became very noticeable. In 1912, the author was sent to 

 investigate and at once resorted to isolation, with the result that over 

 800 head of cattle, the then survivors of 1,100, suffered no loss in 1913 

 in the area which was the centre of disease in 1912. They were care- 

 fully watched for about six months after the fly season, all infected and 

 suspected animals being removed before the flies again became numer- 

 ous. During April and May, 1912, some 200 cases were seen, whereas 

 between February and May, 1913, only five cases were discovered, 

 every one of which occurred in a suspected herd. If a cyclical trans- 

 mitter had been present, isolation would have been useless, as the disease 

 could not have been confined to certain herds. Had ticks played the 

 part of intermediary host the disease would have spread likewise. 

 Tabanidae and Stomoxys are the commonest and most numerous 

 blood-sucking flies in the district. They become very numerous in 

 December and remain so until about the middle of April. From 

 January to April, Tabanus fuscipes swarms in thousands. When these 

 flies are numerous and most active, during the heat of the day, the 

 cattle crowd together for mutual protection and the conditions are 

 consequently extremely favourable for mechanical transmission. As 

 an experiment, two kraals, A and B, were erected within ten yards of 

 each other on the 25th February 1913. One contained two healthy 

 cows and a heifer, and they were still healthy in July, when the author 

 left. The other kraal contained two healthy tested cows and two 

 infected ones. The healthy cows were found to be infected on the 

 12th and 26th April respectively. The cattle from the two kraals 

 were allowed to graze over the same ground, but never together. The 

 kraals were occasionally changed to see if mosquitos in them would act 

 as transmitters. Dogs, sheep and goats were exposed to infection 

 by mixing infected and healthy animals, but no infection resulted. 

 Tabanidae and Stomoxys were fed for cyclical and mechanical trans- 

 mission, but no positive results were obtained. Dogs allowed Stomoxys 

 to feed freely, but never Tabanidae, biting furiously at these on their 

 approach. It is therefore concluded that mechanical transmission 

 took place with Tabanidae as the agent, and that cattle only became 

 infected because of the extremely favourable circumstances obtaining, 

 viz., the crowding of them together in the day-time. The identity 

 of the trypanosome concerned was not ascertained. The course of 

 the disease in cattle was chronic. 



Jack (R. W.). Tsetse Fly and Big Game in S. Rhodesia. — Bull. Entom. 

 Research, London, v, pt. 2, September 1914, pp. 97-110, 2 maps. 

 This article discusses the problem as to whether the presence of big 

 game is necessary for the well-being of Glossina morsitans. Game 

 is fairly abundant all the year round in the fly belts of 

 S. Rhodesia, and never altogether absent. Two districts, along the 

 Gorai and Hanyani Rivers, appeared to be exceptions to this, fly 

 being abundant along the Gorai in October and November, when 

 there is no game there, and scarce on the west bank of the Hanyani, 

 where game is normally abundant at that time. But it is contended 



