118 C. E. Moss, W. M. Rankin and A. G. Tansley. 
now the natural dominant on many of the sandy soils of southern 
England, as on the Eocene sands and overlying “plateau gravels” 
in both the London and Hampshire basins, and on much of the 
Lower Greensand fringing the north and west of the Weald. There 
is good evidence, however, of the widespread introduction of the 
Scots pine into southern England in the eighteenth century, if not 
earlier. This tree is undoubtedly particularly well suited to the 
soils in question, and it has spread and is still spreading over the 
heaths of these regions by means of self-sown seed. On the 
Lower Greensand, however, the pinewoods alternate with oak- 
woods; on the shallow soils with woods of Quercus sessiliflora mixed 
with birch and beech, all three undoubtedly native trees in the 
south of England; and we cannot therefore hastily conclude that 
Scots pine is the original dominant on these soils. 
These considerations lead us to believe that woods belonging 
to the fifth type, i.e., those in which the original species have been 
entirely replaced by others, are in most cases not really difficult to 
identify. The species actually present differ from the regular type 
for the given soil and climate. The same criterion will also apply 
to woods belonging to the fourth type. The scattered “ aliens ” are 
identified because chey are not the regular associates of the dominant 
on the soil in question, or because of their known history, or because 
of their general geographical distribution. There are of course 
some difficult cases here also ; but they are certainly far fewer than 
might be expected by those who have no experience of the kind of 
knowledge obtained by the systematic exploration of the plant 
associations of a given region, and their comparison with those of 
other regions. 
One general conclusion at which we have arrived is that the 
existing English woodlands have for the most part been altered in 
their essential characters to an extent which may appear surprisingly 
slight to those unfamiliar with the actual facts of distribution. 
This is no doubt largely due to the innate conservatism of the 
English landowner, as well as to the backward state of forestry 
practice in this country. 
Coppice and “ Copse.” 
A general feature of the woodlands of southern England, as 
opposed to those of the north, is the great prevalence of coppiced or 
