THE PLANTS OF THE GRAMPIANS. 51 
the heights at which the different species were collected are 
commonly indicated; sometimes this is done only by single 
figures, to show the height of one station; sometimes by 
two figures, to indicate respectively the lowest and highest 
habitats. Though it cannot be supposed that the species 
existed only at the heights at which they chanced to be 
observed by the travellers, yet these indications suffice to 
show, in a general way, the changes of the Flora in connection 
with changes of elevation. This good example has been fol- 
lowed by Meyer, in his account of the plants observed during 
his Travels about the Caucasian mountains. And within 
these few years, we have had a flora of the Dovrefield, in 
Norway, in which the same plan is carried out. (See Biel- 
schmied's German Edition of the Swedish Reports, for 1837, 
Dp. 389, &c.) Several years ago, too, some tables exhibiting 
the hishest and lowest stations of the plants of France were 
published by the celebrated De Candolle. And other bo- 
tanical authors have also indicated the range of elevation for 
several species on the mountains of Europe and in other parts 
of the globe. 
Wahlenberg has mostly taken a different method for 
showing the connection of plants with altitude. In his ad- 
mirable floras of Lapland, Northern Switzerland, and the 
Carpathians, he has first divided the tracts of country, whose 
plants were to be described, into ascending stages or regions, 
characterised by the presence or absence, or the predomi- 
nance, of conspicuous or remarkable species; and the rela- 
tive heights of the other species are then shown by naming 
the regions in which they have been observed by him. Se- 
veral other botanical writers have adopted a similar plan, and 
worked it out with more or less accuracy and completeness ; 
So that, speaking in general terms, we may say that the 
heights, absolute or relative, at which plants grow on the 
mountain ranges of northern and western Europe, (Spain ex- 
cepted), are tolerably well known. Britain has here been 
rather behind-hand. 
In the small volumes, and the minor papers scattered in 
E 2 
