ey
would naturally attain a greater size in lower and warmer levels. The
leaves, also, and fruits of each species, are continually found immersed
in the moss along with the parent trees; as, for example, the leaves and
acorns of the oak, the cones and leaves of the fir, and the nuts of the
hazel.

_Recent origin of some peat-mosses._--In Hatfield moss, in Yorkshire,
which appears clearly to have been a forest eighteen hundred years ago,
fir-trees have been found ninety feet long, and sold for masts and keels
of ships; oaks have also been discovered there above one hundred feet
long. The dimensions of an oak from this moss are given in the
Philosophical Transactions, No. 275, which must have been larger than
any tree now existing in the British dominions.

In the same moss of Hatfield, as well as in that of Kincardine, in
Scotland, and several others, Roman roads have been found covered to the
depth of eight feet by peat. All the coins, axes, arms, and other
utensils found in British and French mosses, are also Roman; so that a
considerable portion of the peat in European peat-bogs is evidently not
more ancient than the age of Julius Caesar. Nor can any vestiges of the
ancient forests described by that general, along the line of the great
Roman way in Britain, be discovered, except in the ruined trunks of
trees in peat.

De Luc ascertained that the very sites of the aboriginal forests of
Hercinia, Semana, Ardennes, and several others, are now occupied by
mosses and fens; and a great part of these changes have, with much
probability, been attributed to the strict orders given by Severus, and
other emperors, to destroy all the wood in the conquered provinces.
Several of the British forests, however, which are now mosses, were cut
at different periods, by order of the English parliament, because they
harbored wolves or outlaws. Thus the Welsh woods were cut and burned, in
the reign of Edward I.; as were many of those in Ireland, by Henry II.,
to prevent the natives from harboring in them, and harassing his troops.

It is curious to reflect that considerable tracts have, by these
accidents, been permanently sterilized, and that, during a period when
civilization has been making great progress, large areas in Europe have,
by human agency, been rendered less capable of administering to the
wants of man. Rennie observes,[1010] with truth, that in those regions
alone which the Roman eagle never reached--in the remote circles