NATURAL CONDITIONS OF PLANTS. 11 
your streams, for your own sakes, but more 
especially for that of your children and grand- 
children.” 
REST. 
46 The meanest herb we trample in the field. 
Or in the garden nurture, when its leaf 
In autumn dies, forebodes another spring, 
And from short slumber wakes to life again,” 
All plants require rest, and obtain it in some 
countries by the rigor of winter ; in others, by 
the scorching and arid heat of summer. Culti- 
vators often fail in their attempts to grow certain 
plants from want of attention to this essential 
point. Thus, most Alpine plants, which enjoy 
an unbroken rest under the snow for several 
months, are very difficult of culture in our mild 
and varying winters. Messrs. Balfour and Ba- 
bington, whilst recently exploring the lofty moun- 
tains of Harris, found the climate to be so 
modified by the vicinity of the great Atlantic 
Ocean, that, notwithstanding their northern lati- 
tude (68°), many of the species inhabiting the 
Highland districts of Scotland were wholly 
wanting, and the few which they saw were con- 
fined to the coldest and most exposed spots. 
From the same cause many plants grow there 
which are not known to grow in so northern a 
latitude in Britain. 
