242 THE PLANTS OF THE GRAMPIANS. 
across Scotland about the latitudinal parallel of 57°, and 
which were spoken of collectively under the general desig- 
nation of the “ Grampians.” 
Those explanations were introductory to two tabular cata- 
logues of all the species of phanerogamous plants said to 
grow on those mountains, having been seen by myself there, 
or reported to have been found by other botanists. In the 
first table, the names of the plants followed each other 
according to the heights of the Joftiest spots on which the 
different species had respectively been observed ; and in those 
instances where I had seen the same species in different 
portions of the general chain, the heights of a second and 
third locality were likewise added. A second and shorter 
list included the alleged localities of some species which had 
not been seen amongst those mountains by myself, and the 
localities for which had been too vaguely indicated by others, 
for their heights to be estimated with any confidence of 
accuracy. 
In order to illustrate completely the ranges of altitude for 
the several species, as far as yet ascertained, it is necessary 
to add a similar account of their Jower limits. For this 
purpose we shall require an enumeration of those species 
only which seldom or never descend to the low grounds, 
except in localities more northerly than the tract of moun- 
tains under consideration. By far the greater number of the 
plants included in the first of the former tables, may be 
found on the low plains or in valleys southward of the 
Grampians, so that their lower limits become questions of 
latitude, not of elevation, and may here be left out of con- 
sideration. 
In attempting to ascertain the lower limits of the species 
in respect of absolute altitude, we unavoidably increase the 
space of country over which our observations must extend, 
and thus proportionably increase the number of local varia- 
tions in height, connected with the modifying influence of local 
peculiarities of the surface. Alpine plants in general descend 
lower on the northern, than on the southern sides and bases of 
