S42 SCIENCE IN AFRICA 



gill-nets. This fish is restricted to the shallower parts of the lake, 

 and in 1927 the governments concerned, fearing that the ngege 

 was being over-exploited, organized the Fishing Survey of Lake 

 Victoria, under Mr. Michael Graham of the Ministry of Agri- 

 culture and Fisheries. The cost was shared between the govern- 

 ments of Kenya, Uganda, and Tanganyika. Some six months were 

 spent on the lake, and the report by Graham (1929) is an exhaus- 

 tive analysis of the ngege fishery, backed by hydrographic and 

 ecological data, with accounts of the other resources which might 

 repay exploitation. As a striking instance of the lack of scientific 

 knowledge prior to the fishing survey, the ngege of commerce, 

 which had been eaten every day by Europeans in Nairobi since 

 the fishery was started, proved to be a species unknown to science. 

 This work was followed in 1 929 by a similar survey of Lakes Albert 

 and Kioga for the Uganda Government by E. B. Worthington, 

 the report on which (1929) stressed the value of a fishery for 

 Albert perch [Lates) and for Citharinus in Lake Albert, and sug- 

 gested methods which could be applied with advantage in both 

 lakes. As a result of the Cambridge Expedition of 1 930-1, Wor- 

 thington (1933a) published another economic report on the 

 Uganda fisheries. In addition to the official reports, the scientific 

 results of these expeditions have been published in technical 

 journals, notably the results of the Cambridge Expedition (1933-6) 

 in a series of nineteen papers. One object of these and similar pub- 

 lications has been the identification and classification of the num- 

 erous varieties of fish. The classical work on African freshwater 

 fish by G. A. Boulenger (1909-16) is somewhat out of date, so the 

 fish fauna is now treated lake by lake in papers by Dr. C. Tate 

 Regan and Miss Trewavas on the family Cichlidae and by E. B. 

 Worthington and Miss Ricardo on the other families. Lakes Vic- 

 toria, Rudolf, Baringo, Albert, Kioga, Edward, Tanganyika, 

 Nyasa, Bangweulu and a number of smaller waters have been 

 dealt with in this way,^ and in 1937 Miss Ricardo extended the 

 investigations by field work on Lake Rukwa, where a commercial 

 fishery has recently been started. The ecology of lakes in the 

 Kenya rift valley has been studied by Miss P. M. Jenkin (1936). 



1 Many of the publications are not referred to here or in the bibHography but full 

 information can be obtained by reference to the Freshwater Biological Association 

 of the British Empire. 



