THE FOREST PERIOD.
Subsequently to Palæolithic times, the physical conditions over
Eurasia changed greatly, and at the commencement of Neolithic times
the conditions were favourable for the growth of forests over wide
regions of that continent. At the commencement of the Forest period
the physical conditions were very much the same as they are at
present, though minor changes have of course taken place since then,
including probably a submergence of large parts of Britain to a depth
of about fifty feet beneath its former level, as indicated by the
existence of Neolithic submerged forests round many parts of our
coast-lines.
The Forest period may be best subdivided for local purposes by
reference to the civilisation of mankind at different times, and in
this way we obtain the following divisions:
Historic Iron age.
Prehistoric Iron age.
Bronze age.
Neolithic age.
A classification may also be based upon changes in the flora. In
Denmark the peat deposits of this age are divisible into five layers,
characterised by different dominant forms of trees. These are as
follows in descending order:
Fifth layer: Beech ... Iron age
Fourth layer: Alder
Third layer: Oak ... Bronze age
Second layer: Scotch Firs ... Neolithic age
Lowest layer: Poplar.
In our own country the forest growth has been much interfered with by
man, but the lower fenland peat gives a good example of the material
formed by forest growth. It is not necessary to touch on the various
accumulations which are now being formed in different parts of our
island, except to remark that the deposits of the Forest period give
indications of earth-movements on a small scale, which is well seen in
the fenland, where the forest peat is covered in places by a "buttery
clay" with _Scrobicularia piperata_ indicating submergence, and above
this is a marsh peat.
The flora and fauna of the Forest period are practically those of the
present day, though the larger forms of mammalia have disappeared one
by one. The Irish elk and _Bos primogenius_ probably became extinct
early in the period, while as far as Britain is concerned the wolf,
bear, and beaver have disappeared within historic times.
The relics of man deserve passing notice. The Neolithic period is
characterised by the absence of metal instruments, though those made
of stone were much more highly finished than those of Palæolithic
times, and were often ground and polished. The first metal which was
largely worked was bronze, which gradually replaced stone, though
stone was extensively used in the Bronze age, as indicated by the
imitation of bronze implements in stone. The Bronze age in turn was
replaced by the Prehistoric iron age; at first, when iron was scarce,
bronze implements were merely tipped with iron, but ultimately the one
metal was practically replaced by the other.
The date of the Palæolithic period is unknown; no approximate date can
be satisfactorily assigned to it, but various calculations, founded on
different data, have been made as to the age of the Neolithic period,
and several of them agree in placing it at about 7000 years from the
present time.
It will be seen that no sudden and violent change marks the incoming
of the human race, which to the geologist is but one of a large number
of events which have followed each other in unbroken sequence, and
accordingly the thread of the story where abandoned by the geologist
is taken up by the antiquary, and passed on by him to the
historian[118].
[Footnote 118: The student may obtain information concerning the
Neolithic age in Britain in Boyd Dawkins's _Early Man in Britain_; Sir
J. Evans' _Early Stone Implements of Great Britain_, and Sir J.
Lubbock's _Prehistoric Times_. In the latter work he will find a good
account of the Neolithic remains of Denmark and of the Swiss Lake
dwellings. For information concerning the Bronze age he should consult
Evans' _Ancient Bronze Implements of Great Britain_. The varied Danish
antiquities of Neolithic and Bronze ages are figured in H. P. Madsen's
_Antiquités Préhistoriques du Danemark_. The Prehistoric fauna of the
fenlands is described in Sir R. Owen's _History of British Fossil
Mammals and Birds_.]