CROP-PLANTS 339 



India where it is second only in importance to sorghum as a dry- 

 land cereal. 



It is uncertain whether the finger millet [Eleusine coracana) is of 

 Afincan or Asiatic origin. Africa certainly shows a greater variety 

 in the number of types which are grown, but the cultivation of 

 finger millet is largely confined to certain tribes in East and Central 

 Africa. 



West Africa has three other indigenous cereal crops. Two of 

 these are species of Digitaria, which are known by the name of 

 'Hungry rice' and a cultivated rice [Oryza glaberrima), which is 

 derived from the wild species 0. barthii, and which occurs from the 

 Gambia to Nigeria in numerous varieties. 



At least three species of pulse crops are of African origin. The 

 principal of these is the cow pea {Vigna unguiculata) , which is a 

 common crop of mixed cultivation throughout Africa and occurs 

 in numerous varieties representing markedly different characters 

 in the grain. Voandzeia subterranea, the Bambarra groundnut, is 

 confined to Africa and Madagascar and occurs throughout the 

 more tropical parts of the country. It possibly reaches its highest 

 development in Nigeria, where it is a crop of some significance. 

 Kerstingiella geocarpa is another very similar African crop which is 

 confined to West Africa. Cajanus cajan is widely distributed through 

 Africa and is probably of African origin, but if so it must have been 

 introduced into India at a very early date, as many specialized 

 varieties are now grown in that country. 



Of oil-seeds, Sesamum orientale is undoubtedly of African origin, 

 as the allied wild species are only found there. It must have found 

 its way into Asia at a very early date; for India, Burma, China, 

 and Japan have all developed many distinct and specialized 

 varieties. It was introduced to the New World at the time of the 

 slave trade, and is still grown in the Garribean area for domes- 

 tic use. The oil-palm, which is always associated with man, 

 belongs to Africa, and there can be little doubt that man has 

 played his part in the development of the higher oil-yielding 

 types. 



West Africa has its own indigo industry based on an indigenous 

 species o^ Indigofera. The artificial hills, which are such a prominent 

 feature of the landscape in the neighbourhood of the northern 



