CHAPTER XVI. 



WOODS AND FORESTS. 



It is only under the most favourable circumstances, 

 and in places which enjoy the very best conditions of 

 light, moisture, and shelter from wind, and only upon 

 the richest soils, prepared beforehand by a long series 

 of former vegetations, that woods and forest are able to 

 develop. 



They represent, in fact, a final effort of Nature in 

 the way of natural vegetation. In them, the organic 

 material produced ev^ery year is infinitely greater than 

 that formed by any other association of plants. In 

 woods, also, there is extreme division of labour, minute 

 specialisation amongst the constituent plants, and a very 

 much greater organisation than occurs in Mosses, 

 Moors, Grasses, or other natural plant communities. 

 It is therefore necessary to give a short account of 

 Woods considered as ORGANISMS. 



In a previous chapter, the body of a plant was shown 

 to be composed of many cells, each of which has its 

 own work, but is yet entirely subordinate to the welfare 

 of the whole plant. Very much the same may be said 

 of the different plants which constitute a wood. Each 

 has its own special function, and its work benefits the 

 whole wood as well as itself Moreover, its development 

 seems to be controlled by laws similar to those that 

 govern the individual cells in vegetable tissues. Woods 



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