304 PLANT LIFE. 



have an absorption system and an assimilation system^ 

 and have made provision for the breaking up and 

 destruction of useless or inefficient individuals. They 

 grow and die ; they have to compete with other sorts 

 of vegetation ; and in many other ways they may be 

 compared to a living vegetable. 



This method of considering plants in associations 

 has been implicitly followed in some of the preceding 

 chapters. It is based on the work of Eugene Warming 

 and others, who have, in this respect, produced a 

 thorough revolution. Yet the idea is not new ; for, 

 though the botanist has never been able to see the 

 wood for the trees, even prehistoric man must have had 

 a very thorough idea of the meaning of such terms as 

 "Wood," ''Marsh," "Moor," and "Loch." 



The chief difficulty arises from the specific and 

 individual differences. An attentive observer will find 

 slight differences in every woodland ; and, of course, the 

 tropical rain-jungle of the West Coast of Africa is 

 totally different from the New Forest in England. But 

 any ordinary sort of deciduous plantation in Britain, 

 will distinctly show most of the features which are 

 described here, provided that it is of some extent, and 

 is not grazed by cattle, or in a very bad state of 

 decay. 



The most important points are: (i) The Foliage 

 surface of the trees ; (2) the covering or "Floor" of the 

 wood ; (3) the Undergrowth of shrubs and creepers ; 

 (4) the Bark-flora, chiefly Mosses and Lichens ; (5) the 

 Subterranean system ; (6) the Plants on the edges or 

 borders. 



Thus, if one imagines a section through a wood, such 

 as is roughly shown in the diagram, there would be 

 first the dense leaf-surface, or foliage dome, formed by 



