THE PRINCIPLES OF BIOLOGY. 
337 
is as follows:—The Scandinavian species are fourteen in 
number. Of these all but two are in the Alps, all but four in 
the Pyrenees, and almost all are North American. The Alpine 
saxifrages number forty-four, of which twelve only are 
Scandinavian, while twenty-five are Carpathian, twenty 
Pyrenean, and eight Altaic. 
Mr. Ball points out that of 1,157 species characteristic of 
the Alpine Flora, two-thirds are found in the Carpathians, 
one-lialf in the Pyrenees, and one-fourtli in the Altai. 
When we pass to the south of the Mediterranean the 
contrast is amazing, the entire Algerian Atlas yielding seven 
species only of Alpine plants. 
The Flora of our own country, although of comparatively 
small interest, owing, as I believe, to the destruction of the 
greater part of the indigenous plants at the time of the 
submergence in the glacial age, presents, nevertheless, some 
curious features. 
The total number of species is 1,6G5 ; of these, 1,465 are 
Germanic or Scandinavian, the majority of which are scattered 
over the whole of northern temperate Europe and Asia. 
They may be subdivided into plants widely spread in 
Britain, Germanic plants confined to the eastern side of 
England, mountain plants (Scandinavian or Alpine). 
Deducting aliens and uncertain segregrates, we have left 
119. Of these, 114 are species belonging to south-west Europe 
and three are American. It is worthy of remark that there 
does not exist throughout the whole extent of the British 
Isles a single well-defined endemic species. 
A few words upon one of the most curious points 
connected with the distribution of plants, and these remarks 
must be brought to a conclusion. I refer to the contrast 
which different genera present in their capacity for receiving 
specific modifications under the influence of varying external 
forces. On the shores of the Mediterranean the bramble is 
almost stable ; the only form that is met with, or nearly so, 
is liubus discolor. In the northern part of temperate Europe 
its variations are very numerous. On the other hand, the 
genus Medicago is nearly stable in the zone of Rubus , and 
highly plastic on the Mediterranean coasts. Astragalus pre¬ 
sents differences still more remarkable than those of Medicago. 
In England there are only three species, in France twenty- 
four, in Spain thirty-nine; while Boissier, in his “Flora 
Orientalis,” including only the extra-tropical countries from 
Greece to the borders of India, enumerates no fewer than 757 
species. 
