268 BRITISH PLANTS 
seedlings, saplings, and great aged individuals are all 
mixed together, competing freely with one another for 
room and light. In plantations it is different ; many, if 
not all, of the trees are of the same age; aliens arecommon | 
—e.g., chestnuts, sycamores, elms, and firs—and trees not 
common to the district or soil—e.g., pine in most parts of 
the country, and the beech in the west ; and if the planta- 
tion is recent the ground-vegetation is not typically wood- 
land at all. In the course of time, however, these out- 
of-place inhabitants of the undergrowth disappear, and 
true woodland forms take their place. 
Copses. 
Cutting or coppicing also modifies woods, and most 
of our woods are cut periodically, either gradually or 
en masse. In woods trees are generally felled one here 
and one there, and new saplings put in their place. In 
copses, on the other hand, the whole wood is periodically 
cut down, and then allowed to regenerate itself from the 
boles left in the ground. In the latter case the shade of 
the wood is banished, and with it most of the shade- 
loving woodland plants. Sun-loving forms come in from 
the adjacent pastures and heaths, and maintain their 
position until a new wood springs up from the ruins of 
the old, and increasing shade drives them out. 
From what we have said, it is clear that although 
natural woods are not common in this country, many 
artificial woods—especially those which have been derived 
from ancient ones, or old plantations of native trees, and 
even coppiced woods before the trees are cut—stand very 
near natural woods, and give us a good idea of what the 
primitive woodland-vegetation of these islands was like. 
Thickets. 
In rough, uncultivated, and especially hilly places, and 
on the rocky sides of river-Valleys, bushes and shrubs 
become more abundant than trees. In these places the 
soil is very shallow, and tree-growth is often dwarfed or 
stopped altogether. The most abundant bush in this 
country is the hazel, which in former times was extensively 
planted in woods for economic purposes, especially among 
oaks and ashes, which were periodically coppiced. 
