BOTANY 163 



description of the main regions, and discussed the role of forests in 

 development. Lamy (1933) has studied the forest land of Ruanda- 

 Urundi. Lebrun (1932) has surveyed the Ubangi district and 

 (1936) has summarized all the botanical work on the Congo forest 

 flora up to that date. 



North Tropical Africa 



The work of the late Dr. T. F. Chipp, when Conservator of 

 Forests on the Gold Coast and subsequently at Kew, stands out 

 pre-eminent, especially his analysis of the Gold Coast forests (1927), 

 an analysis of the tropical forest from the modern successional 

 point of view. Chipp wrote also two general papers (1930 and 

 1931) analysing the vegetation over much of north tropical Africa. 

 Professor P. A. Buxton (1935), when working on tsetse flies in 

 northern Nigeria, gathered interesting data on the relation of 

 climate to seasonal changes in vegetation. W. D. MacGregor 

 (1934) silvicultural research officer in Nigeria, has shown how 

 closely ecology and silviculture are related in that country, with 

 especial reference to the mixed deciduous forest. 



For the French territories A. Chevalier (191 2) has produced a 

 useful vegetation map of the whole of West Africa on the scale 

 1 :3,ooo,ooo, and A. Meunier (1923-33) of the Ministry for Colonies, 

 Paris, a series of six economic maps of French West Africa on the 

 same scale. Four of these deal with vegetable resources, one with 

 wild fauna and one with domesticated animals. Chevalier (1933) 

 has summarized the botanical regions of all north-west tropical 

 Africa. L. Lavauden (1927) has recorded much evidence con- 

 cerning the degeneration of vegetation, which is thought by many 

 to be the result of progressive desiccation, rather than of human 

 activities. He considers that though protection may win back 

 some of the vegetation, the Sahara will continue to advance. 

 O. Hagerup (1930) has made a useful study in the Timbuctoo 

 region of the Sahara: the distribution of plants was found to be 

 remarkably uniform since their general method of dispersal is by 

 wind. R. Maire (1933 and 1935) has described the flora of the 

 Central Sahara and Tibesti Mountains in two long papers, the 

 results being discussed by Hutchinson (1936). For the Cameroons, 

 J. M. Dalziel (1930) studied the flora of the high mountain region 



