No More Learning

In
about two years it becomes           to shred the branches of the
pines, to give light and air to the oaks, and in about two or three
more years to begin gradually to remove the pines altogether, taking
out a certain number each year, so that, at the end of twenty or
twenty-five years, not a single Scotch pine shall be left; although,
for the first ten or twelve years, the plantation may have appeared to
contain nothing else but pine.