154 
MISCELLANEOUS. 
[Part II. 
ciple is very apparent in the step-stands in green¬ 
houses; though, probably, the origin of these 
stands may be the greater facility they give to 
see and to water the plants. But if the plants 
stood on the area of the base of the stand, each 
would be shaded all round by its neighbours, 
and would receive light only from above. The 
base of what is called in Hampshire u a hanger,” 
or a hanging wood, would not support as many 
trees with full heads as stand on the hill-side. 
Let us conceive these 
“ Densas, umbrosa cacumina, fagos ” 
to be sunk vertically downward from their beau¬ 
tiful gradations, till their roots shall stand on 
the base of the hanger. The long one-sided 
columns of green will be submerged, smothered, 
and killed below the one common level of the 
tops, and the plants will be deprived almost 
entirely of their organs of respiration and trans¬ 
piration. But besides this greater space for the 
heads, there is also greater space for the roots of 
plants growing on the side of a hill, than if they 
had only the base of the hill-side to grow on. 
For roots, as has been shown, have the power of 
following the surface of the earth, be the incli¬ 
nation upward or downward what it will. And 
