case. In the forest bed near Cromer, on the coast of Norfolk, remains both of the Spruce Fir and Scotch
Fir have been found. These, however, lie below the boulder clay or drift of the Glacial Epoch, and refer
to a state of things antecedent to the great changes effe&ed by that period. Remains, however, have been
found in the peat beds of Orkney and Shetland, which were certainly subsequent in date to it. According
to Dr Neill, cones of the Silver Fir have been found in the peat-moors of Orkney; and a large tree,
referred to that species on what appear , to us questionable grounds, has been found in Unst, one of the
Shetlands. The statement is made by Mr T. Edmonston, in a list of Shetland plants published in 1841
in the " Annals and Magazine of Natural History," vol. vii. p. 295.
" EXTINCT SPECIES.—PI««? Picea.—An old man told me that he found a Fir-tree about 6 feet below the surface of the ground when digging
peat at the east side of Unst. It was about 40 feet in length and about 6 feet in circumference. It was much decayed on the outside, but quite
sound in the heart. The cones of the Silver Fir (according to Dr Neill) have been found in the peat-moors in Orkney, although I am not aware
of their being observed in Shetland; and as this species seems, when planted, to succeed the best of all its tribe, it may be supposed that the
tree in question was of this species."
We can neither agree with Mr Edmonston's premises nor his conclusion. If he refers to Shetland,
the Silver Fir will not grow there at all; if he refers to Scotland, it does not succeed best of all there.
Even in Orkney we all know that no natural wood grows there (with the exception, we believe, of some
bushes of Mountain Ash, Birch, and Aspen Poplar found in some sheltered nooks in the Island of Hoy);
and with regard to introduced trees, Dr William Traill of St Andrews tells us, in an interesting paper
lately read before the Botanical Society of Edinburgh (May 9, 1867), "On the Submarine Forests of
Orkney," that although the old notion that trees would not grow at all in Orkney is now quite disproved,
still "evergreen Firs and Pines in general do not appear suitable." As to Scotland, again, proof is
surely not required that the Spruce is hardier than the Silver. We say so nostro periculo, and shall
assume that our statement is not disputed. The geographical distribution of the two trees at once shews
that it must be so. If we look to the isothermal lines of these species in the present day, we find the
northern limit of the Spruce in the north of Norway and Sweden, while that of the Silver is south of
Breslau and Dresden. Moreover, as the climate of Europe, according to geologists, has gradually ameliorated
since the close of the Glacial Epoch (four successive periods, each milder than the other, having been
made out by M. Lartet and accepted by other geologists), the tree which is most in correspondence with
such colder temperature is rather the Spruce than the Silver. So far as regards the Unst tree, therefore,
the probability is that it was a Spruce. The only other authority for cones of the Silver having been
found, either in Orkney or Shetland, is that above noticed, of Dr Neill, that they had been found in
the peat-mosses of Orkney. Now, in the first place, admitting the reference to Dr Neill as correct,
although we have not been able to verify it, Dr Neill was more of a horticulturist than an
arboriculturist; and, without depreciating his knowledge more than we think he himself would have
readily admitted, it is possible that he may have referred the cones to the Silver by mistake,
instead of to the Spruce. We are led to this remark by certain doubts which we feel as to the
possibility of the cone—that is, the entire cone—of a Silver Fir being preserved in a fossil state. In its
mature state it falls to pieces, and all that remains for preservation are the single scales or the central core,
neither of which, of course, fulfils the condition implied in the term cone; and in its young green state it
has not yet acquired the woody texture of the scales which fits them for preservation, and is composed
mainly of chlorophyll, which comparatively speedily decays. There probably is a sort of interregnum, or
period when, having lost the flaccidity of extreme youth, they have acquired the consistency of age without
its fragility; but we have never been able to hit upon the happy moment. All our specimens of cones
of Silver Firs either shrivel up or fall to pieces, unless we provide against the latter contingency by tying
them up in a bag of netting. Neither have we ever seen a fossil cone of any species of Silver Fir; and
the one or two which are recorded seem to us very questionable.
We therefore feel little doubt that it was the Spruce and not the Silver which has left its remains in
Orkney
Orkney and Shetland. The bearing of this fact on the past geography and geological history of Europe
is stated as follows by Mr Andrew Murray (" Geographical Distribution of Mammals "):—
" Iceland, Greenland, and Spitzbergen, all three, possess nearly the same flora, and that flora European; they must either have been united
to cach other and to Europe in one line, or united by different necks of land to the Continent; which latter supposition, although not impossible,
is inconsistent with the close similarity of the floras of these lands, with the configuration of the bed of the neighbouring sea, and with
other fafts having a like bearing.
"The European charader of the plants and insefts of Greenland, Iceland, and Spitzbergen is sufficient evidence that they must
have been connected with Europe in some way, but that alone throws but little light on the point of connexion. It may have been by
Norway, by Nova Zembla, or by Britain. The following considerations shew that it must have been by the latter:—
" No tree now grows in Orkney or Shetland; the only ligneous things that do grow are the Delula alba and the common Juniper,
both merely existing as shrubs; but at 6 feet beneath a peat-bog, trees, tranches, leaves, and cones, ascribed to the Silver Fir, have been
found—one tree in particular, of 6 feet in circumference and 40 feet in height, being recorded by Mr Edmonston as having been found
in peat in Shetland.
"When did these trees grow, and what was the climate of Britain then? Was it really milder then than now, as we should be
inclined to exped, from the fact of these trees being found in Shetland, where they will not now grow ? As to the date of their growth
away every trace of peat-bogs from the surface of the land. Were a Swiss glacier to meet a peat-bog in its course, it would soon plough
it up, and scarify the ground to tile very bone below. It is plain, therefore, that the tree must have grown and died, and the peat
been deposited subsequent to the glacial epoch.
" Now, one of two things must have taken place since it grew: either the general climate of the northern hemisphere must have
undergone a change, and that change must have been from warmer to colder; or the individual climate of Shetland must have done so by
an alteration in its configuration and physical condition.
" But the growth of these Firs (if Silver Firs they be and not Spruces) could not be due to any material change in the general climate
of the whole country; for their remains are found in the peat, in company with those of the Scotch Pine and Spruce Fir, and as these are
the same trees that now grow in the corresponding isothermal line on the Continent, no general alteration from warmer to colder can
well have taken place over the whole hemisphere; and as it is only on the Continent, or in lands not exposed to the sea, that they thrive
in that latitude, it may be inferred that at the time they grew there, the Shetlands were either not islands, or not such small islands.
"But the Shetland Islands rise nearly precipitously from a wide submarine plain seventy-four fathoms deep, which extends from
these islands to within no great distance of the coast of Norway. Their form, therefore, shews that any increase on their size could only
be obtained by such an elevation as would unite them to the Continent, from Denmark southwards; and there is little doubt that that
must have been the position of matters when the trees in question grew on these islands. Along the west coast of Norway a deep
channel extends in continuation of that of the Baltic. That sea then must have trended away up by the west coast of Norway, and
Britain must have been joined on to the present Continent from the Shetlands to the north of Denmark, all south of a line drawn
between them being much less than seventy-four fadioms in depth. The Rhine and the Elbe, so soon as by the subsequent rise of
the land they came into existence, probably emptied themselves into the Baltic."
But leaving the past, let us turn to the present and see what is the distribution of the species at the
present day. Beginning with the north, we find that the polar limit of the Spruce Fir in Western Russia is
68° 15', and in Norway 67°. In the latter, Dr Schubeler, in his " Synopsis of the Vegetable Products of
Norway," at the Exhibition of 1862, says that between lat. 63° and 65° it grows almost down to the sea.
Forests of this tree appear up to lat. 66J°, but never beyond lat. 67°. Excluding the still more northern
form, which we describe separately under the name of A. medioxenia, the limit for the Spruce in Norway
may be placed as follows: in the southern districts, at an altitude of 2800 to 3100 feet; under lat. 62°, at
about 2600 to 2800 feet; under lat 64°, at about 1600 to 1800 feet; and in Nordland, at barely 800 feet
above the sea. In Sweden it extends a little more to the north, being found in Swedish Lapland,
according to De Buch and Ch. Martins, as far north as the latitude above mentioned (68° 15' north lat.)
It is said to advance still more to the north in Russian Lapland towards Enare, according to M.
C. A. Meyer (" Carte Geogr. Bot. en Russe ").
Southwards from the above extreme northern limits of the species it extends towards the Baltic,
increasing in abundance until it reaches that sea : it and Pinus sylveslris forming the most extensive forests
in the south-eastern parts of Norway.
It does not occur as a native in the west of Germany: thus, it is not to be found in the floras of
Mecklenburg, of Denmark (Muller, "Flora Fridrichsdalina" and "Fries Summa Veg."), of Berlin
(Kunth), or of Brandenburg (Ruthe). It begins in isolated individuals upon the shores of the Baltic,
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