EXISTING VEGETABLE CREATION. 895 
The case stands differently if we take our ground on the supposition 
that there were originally many primary individuals ; the explanation 
of the geographical botany of the British Islands then becomes 
extremely intelligible. The west of Ireland and the south-west of 
England had in that period, as now, an unusually mild climate, 
especially in winter, considering their position in latitude; in conse- 
quence of which, plants were produced there, common to the 
analogous climate of Spain and the south of France. The Scotch 
and English mountains, distinguished, in both periods, by a polar 
climate, produced nearly the same vegetation as the Lapland and 
Scandinavian mountains. Under this explanation we need have no 
recourse to any German immigration. 
2. Another momentous problem to be solved is the following :—Do 
new species continue to be created; or has the existing vegetable 
kingdom been finally completed ? 
No doubt recent lists of plants growing in any given country or 
tract of land, or in the vicinity of certain towns, contain species not 
enumerated in older lists. But this does not prove that such species 
are of modern creation. It is well known that a much greater amount 
of characters was required by old botanists to distinguish between 
species, than now-a-days; and if we examine attentively the species 
thus added, we shall find that they are of that very form which the old 
botanists would have included under other species ; and they are accord- 
ingly often found united in old herbaria or figures of plants. It often 
happens that plants are actually discovered, which were not formerly 
known to be the produce of a given spot; but in such cases the 
question is not the creation of new species, but of new localities of 
established species. I have on a previous occasion* endeavoured to 
prove that the plants which the ancient Roman and Greek authors 
assigned to the shores of the Mediterranean, as prevailing and 
characteristic there, were the same as those which at present exist. 
The most rational mode of accounting for new species being possibly 
created, seems to be by supposing that a change of climate or soil 
produces a corresponding change in the character of its plants; or that 
some casual difference in the normal type of any given plant, may have 
become permanent by its being isolated. It is in this way that con- 
stant varieties have arisen, which may sometimes even have become real 
* Brewster’s ‘ Edinburgh Journal of Science.’ 
