t20 C. E. Moss, W. M. Rankin and A. G. Tansley. 
leafy plants, many of which are unable to flower. After the coppice 
is cut, the access of bright light provides a great stimulus to 
development; and the previously dormant or weakly vegetating 
plants spring into activity. About the second or third season after 
cutting, the ground vegetation attains its maximum development; 
and, as is well known, the floor of the wood is often covered in 
April and May with sheets of such showy species as primroses, 
bluebells, wood anemones, or red campions. As the new coppice 
shoots grow up from the stools, this active vegetation lessens in 
vigour, and gradually returns to its former condition. 
Relations of Climate and Soil. 
If we assume the position adopted in this paper, that the great 
majority of the existing British woodlands may be regarded as 
natural or semi-natural plant associations, i.e., as being the descen¬ 
dants, more or less modified, of the various primitive types of forest 
that existed in this country, and as bearing unmistakable marks of 
their origin, we have to enquire what are the factors which determine 
the distribution of the different types. An intimate scientific 
knowledge of these factors no one can pretend to possess, but a 
certain amount of information may be gained by considering the 
observed distribution in relation to the different characters of the 
environment. 
If we consider first that class of environmental conditions 
usually comprised under the general term climate, we find that we 
may distinguish two kinds of climatic variation. 
First we have the variation met with in passing across the 
country at a relatively slight elevation above sea level, as exemplified 
by the difference between the climate of Kent, for instance, and 
that of the Lake District, or between the climate of Cornwall and 
that of East Anglia. These differences in climate, considerable as 
they are, have for the most part an effect on the secondary characters 
only of the English woodland associations, i.e., on the presence or 
absence of certain associated species. They do not alter, except 
in the manner to be indicated presently, the general nature of the 
woodland types. For example, the type of woodland which occurs 
on the Jurassic marls of Somerset is identical with that which 
occurs on the chalky Boulder-clay of East Anglia, but in the 
Somerset woods ferns are much more numerous both in species 
and in individuals than in East Anglia, and this difference is 
certainly due to the difference of climate. Of other differences in 
