382 THE SEED AND ITS GERMINATION 



Of these certain species of palm are among the chief. 

 The West African oil-palm (Elceis guineensis) and 

 the coconut palm (Cocos nucifera) are the two leading 

 species. The former is a constituent of most of the 

 native food in West Africa, and it has been extensively 

 planted in other parts of the continent. In comparatively 

 recent years a great export trade in " palm kernels " has 

 been developed, and from these the oil is extracted 

 for various purposes, prominent among which is the 

 manufacture of margarine. The coconut is used very 

 extensively by the natives throughout the damp tropics 

 for food, lighting and other things, and the oily endosperm 

 is very extensively sun-dried and exported as copra, 

 which is used for margarine, soap-making, etc. 



Other important oil-bearing seeds are the " soy bean " 

 (a leguminous plant), linseed (the seed of the flax), 

 and cottonseed (the seed of the cotton plant), the oils of 

 which are all used in making food and for a variety 

 of industrial purposes. After most of the oil is 

 extracted the residue is utilised as cattle food (" cake "). 

 Relation of the Size of the Seed to Dispersal and to 

 the Chances of Life of the Seedling. A large seed con- 

 taining a large amount of food material naturally enables 

 a large seedling to be produced in a comparatively short 

 time, just as a considerable shoot system can be quickly 

 produced from a bulb or tuber : whereas a seedling 

 produced from a small seed uses up its reserves very 

 quickly, and has the laborious work of slowly building 

 up new organic substance from inorganic, with a root 

 and leaf surface which is at first of very limited extent. 

 Provided it finds a suitable spot for germination and 

 growth, the seedling derived from a large seed thus 

 has a great initial advantage in competing with other 

 plants for space and light, because it is less likely to be 



