ne, interested me. In Staffordshire, on the estate of
a relation, where I had ample means of investigation, there was a large
and extremely barren heath, which had never been touched by the hand
of man; but several hundred acres of exactly the same nature had been
enclosed twenty-five years previously and planted with Scotch fir. The
change in the native vegetation of the planted part of the heath was
most remarkable, more than is generally seen in passing from one quite
different soil to another: not only the proportional numbers of the
heath-plants were wholly changed, but twelve species of plants (not
counting grasses and carices) flourished in the plantations, which could
not be found on the heath. The effect on the insects must have been
still greater, for six insectivorous birds were very common in the
plantations, which were not to be seen on the heath; and the heath was
frequented by two or three distinct insectivorous birds. Here we see how
potent has been the effect of the introduction of a single tree, nothing
whatever else having been done, with the exception of the land having
been enclosed, so that cattle could not enter. But how important an
element enclosure is, I plainly saw near Farnham, in Surrey. Here
there are extensive heaths, with a few clumps of old Scotch firs on
the distant hill-tops: within the last ten years large spaces have been
enclosed, and self-sown firs are now springing up in multitudes, so
close together that all cannot live. When I ascertained that these young
trees had not been sown or planted I was so much surprised at their
numbers that I went to several points of view, whence I could examine
hundreds of acres of the unenclosed heath, and literally I could not
see a single Scotch fir, except the old planted clumps. But on looking
closely between the stems of the heath, I found a multitude of seedlings
and little trees, which had been perpetually browsed down by the cattle.
In one square yard, at a point some hundred yards distant from one of
the old clumps, I counted thirty-two little trees; and one of them, with
twenty-six rings of growth, had, during many years tried to raise its
head above the stems of the heath, and had failed. No wonder that, as
soon as the land was enclosed, it became thickly clothed with vigorously
growing young firs. Yet the heath was so extremely barren and so
extensive that no one would ever have imagined that cattle would have so
closely and effectually s