FORESTRY 2O9 



the fast-growing softwood trees of tropical Africa may yet become 

 a possibility, but so far has not yet reached even the experimental 

 stage. 



Since hive bees produce very little wax, commercial beeswax is 

 mainly collected from wild sources. Of these East Africa is the 

 chief source for the British Empire, and a certain amount also is 

 exported from Egypt and the Sudan. Wild honey is collected by 

 natives throughout the African forests and in many places is an 

 important constituent of native diet. The collection of honey 

 and other products is a contributory cause of the degradation 

 of savannah forests, since it is accompanied by extensive annual 

 firing carried out so that native collectors can move easily through 

 areas which are covered annually by tall grass. There can be little 

 doubt that the damage by regular and thorough burning must in 

 the long run outweigh by far the temporary economic advantages 

 derived from these products. 



Medicinal Drugs (see also Chapter VI, p. i66) from trees and 

 vegetation have not yet been found to be of great importance in 

 Africa, though research might affect this position. A few medicinal 

 products, such as Strophanthus seeds from Nyasaland, are regularly 

 exported. Many trees and shrubs are used by natives for medicinal 

 purposes, and the products of others appear to make good certain 

 diet deficiencies, for instance, the leaves of the baobab, which are 

 rich in vitamins (see Chapter XVII, p. 574). To produce local 

 supplies of well-known drugs, some tree species have been intro- 

 duced to Africa, notably Cinchona, plantations of which have been 

 established in several places (see Chapter XII, p. 374). More 

 recently Hydnocarpus has been introduced from India to Uganda 

 and elsewhere, in the hope of producing local supplies of chaul- 

 moogra oil for the treatment of leprosy. 



PESTS AND DISEASES OF FORESTS 



An analysis of recent literature shows that little study has yet 

 been made of pests of purely forest importance. It is significant, 

 however, that the dangers of pests and diseases is greatest in 

 plantations of exotic trees, and also in plantations of some indi- 

 genous trees, such as Iroko {Chlorophora excelsa), made under artifi- 



H 



