In the noble flora of the Coal Measures much still remains to be done in
Scotland. Our Lower Carboniferous rocks are of immense development; the
Limestones of Burdiehouse, with their numerous terrestrial plants, occur
many hundred feet beneath our Mountain Limestones; and our list of
vegetable species peculiar to these lower deposits is still very
incomplete. Even in those higher Carboniferous rocks with which the many
coal workings of the country have rendered us comparatively familiar,
there appears to be still a good deal of the new and the unknown to
repay the labor of future exploration. It was only last year that Mr.
Gourlay[53] of this city (Glasgow) added to our fossil flora a new
Volkmannia from the coal field of Carluke; and I detected very recently
in a neighboring locality (the Airdrie coal field), though in but an
indifferent state of keeping, what seems to be a new and very peculiar
fern. It presents at first sight more the appearance of a Cycadaceous
frond than any other vegetable organism of the Carboniferous age which I
have yet seen. From a mid stem there proceed at right angles, and in
alternate order, a series of sessile, lanceolate, acute leaflets, nearly
two inches in length by about an eighth part of an inch in breadth, and
about three lines apart. Each is furnished with a slender midrib; and,
what seems a singular, though not entirely unique, feature in a fern,
their edges are densely hirsute, and bristle with thick, short hair,
nearly as stiff as prickles. The venation is not distinctly preserved;
but enough remains to show that it must have been peculiar,--apparently
radiating outwards from a series of centres ranged along the midrib.
Nay, the apparent hairs seem to be but prolongations of the nerves
carried beyond the edges of the leaflets. There is a Stigmaria, too, on
the table, very ornate in its sculpture, of which I have now found three
specimens in a quarry of the Lower Coal Measures near Portobello, that
has still to be figured and described. In this richly ornamented
Stigmaria the characteristic areolæ present the ordinary aspect. Each,
however, forms the centre of a sculptured star, consisting of from
eighteen to twenty rays, or rather the centre of a sculptured flower of
the composite order, resembling a meadow daisy or sea-aster. The minute
petals,--if we are to accept the latter comparison,--are of an
irregularly lenticular form, generally entire, but in some instances
ranged in two, or even three, concentric lines round the depressed
centre of the areolæ; while the interspaces outside are occupied by
numerous fretted markings, resembling broken fragments of petals, which,
though less regularly ranged than the others, are effective in imparting
a richly ornate aspect to the whole.
[Illustration: Fig. 125.]
[Illustration: Fig. 126.
STIGMARIA.]
[Illustration: Fig. 127.
THE SAME, MAGNIFIED.]
Ever since the appearance, in 1846, of Mr. Binney's paper on the
relations of stigmaria to sigillaria as roots and stems, I have been
looking for distinguishing specific marks among the former; and, failing
for a time to find any, I concluded that, though the stems of the
sigillarian genus were variously sculptured, their roots might in all
the species have been the same. The present rich specimen does seem,
however, to bear the specific stamp; and, from the peculiar character of
the termination of another specimen on the table, I am inclined to hold
that the stigmaria may have borne the appearance rather of underground
stems than of proper roots. This specimen suddenly terminates, at a
thickness of two and a half inches, in a rounded point, abrupt as that
of one of the massier cacti; and every part of the blunt sudden
termination is thickly fretted over with the characteristic areolæ. The
slim tubular rootlets must have stuck out on every side from the obtuse
rounded termination of this underground stem, as we see, on a small
scale, the leaflets of our larger club mosses sticking out from what are
comparatively the scarce less abrupt terminations of their creeping
stems and branches. In at least certain stages of growth the sub-ærial
stems of Lepidodendron also terminated abruptly (see Fig. 24); and the
only terminal point of Ulodendron I ever saw was nearly as obtuse as
that of Stigmaria.
[Illustration: Fig. 128.
STIGMARIA.]
I have been long desirous of acquainting myself with the true character
of this latter plant (Ulodendron), but hitherto my labors have not been
very successful. A specimen of _Ulodendron minus_, however, now on the
table, which I disinterred several years ago from out a bed of
ferruginous shale in the Water of Leith, a little above the village of
Colinton, exhibits several peculiarities which, so far as I know, have
not yet been described. Though rather less than ten inches in length by
about three inches in breadth, it exhibits no fewer than seven of those
round, beautifully sculptured scars, ranged rectilinearly along the
trunk, by which this ancient genus is so remarkably characterized. It
is covered with small, sharply relieved, obovate scales, most of them
furnished with an apparent midrib, and with their edges slightly turned
up; from which peculiarities, and their great beauty, they seem suited
to remind the architect of that style of sculpture adopted by Palladio
from his master Vitruvius, when, in ornamenting the Corinthian and
composite torus, lie fretted it into closely imbricated obovate leaves.
These scales are ranged in elegant curves, not unlike those ornamental
curves,--a feat of the turning-lathe,--which one sees roughening the
backs of ladies' watches of French manufacture. My fossil exhibited, as
it lay in the rock, what I never saw in any other specimen,--a true
branch sticking out at an acute angle from the stem, and fretted with
scales of a peculiar form, which in one little corner appear also on the
main stem, but which differ so considerably from those of the obovate,
apparently imbricated type, that, if found on a separate specimen, they
might be held to indicate difference of species. It has been shown by
Messrs. Lindley and Hutton, on the evidence of one of the specimens
figured in the "Fossil Flora," that the line of circular scars so
remarkable in this genus, and which is held to be the impressions made
by a rectilinear range of almost sessile cones, existed in duplicate on
each stem,--a row occurring on two of the sides of the plant directly
opposite each other. The branch in my specimen struck off from one of
the intermediate sides at right angles with the cones. We already know
that these were ranged in one plane; nor, if the branches were ranged in
one plane also,--certainly the disposition of branch which would consort
best with such a disposition of cone,--would the arrangement be without
example in the vegetable kingdom as it even now exists. "Our host," says
the late Captain Basil Hall, in his brief description of the island of
Java, "carried us to see a singular tree, which had been brought from
Madagascar, called familiarly the _Traveller's Friend_, Urania being, I
believe, its botanic name. We found it to differ from most other trees
in having all its branches in one plane, like the sticks of a fan or the
feathers of a peacock's tail." I may further mention, that the specimen
which showed me the abrupt cactus-like terminations of Ulodendron
repeated the evidence of Messrs. Lindley and Hutton's specimen regarding
the arrangement of the cone scars on opposite sides, and showed also
that these scars ascended to within little more than an inch of the top
of the plant.
As there are cases in which the _position_ of a fossil plant may add,
from its bearing on geologic history, a threefold interest to the fossil
itself, regarded simply as an organism, I may be permitted to refer to a
circumstance already recorded, that there was a well marked Bechera
detected about two years ago by Dr. Macbean of Edinburgh, an
accomplished naturalist and careful observer, in a thin argillaceous
stratum, interposed, in the Queen's Park, between a bed of columnar
basalt and a bed of trap-tuff, in the side of the eminence occupied atop
by the ruins of St. Anthony's Chapel. The stratified bed in which it
occurs seems, from its texture and color, to be composed mainly of
trappean materials, but deposited and arranged in water; and abounds in
carbonaceous markings, usually in so imperfect a state of keeping that,
though long known to some of the Edinburgh geologists, not a single
species, or even genus, were they able to determine. All that could be
said was, that they seemed fucoidal, and might of course belong to any
age. The Bechera, however, shows that the deposit is one of the Lower
Coal Measures. There was found associated with it a tooth of a
Carboniferous Holoptychius, whose evidence bore out the same conclusion;
and both fossils derive an importance from the light which they throw
on the age of the bed of tuff which underlies the stratum in which they
occur. At least this trap-rock must be as old as the fossiliferous layer
which rests upon it, or rather, as shown by its underlying position, a
little older: it must be a trap of the earlier Carboniferous period.
Further, it must have been, not injected among the strata, but poured
out over the surface,--in all probability covered at the time by water;
and there must have formed over it, ere another overflow of trap took
place, a thin sedimentary bed charged with fragments of the plants of
the period, and visited, when in the course of deposition, by some of
its fishes.
[Illustration: Fig. 129.
SPHENOPTERIS BIFIDA.
(_Burdiehouse._)]
Even among the vegetable organisms of our Coal Measures, already
partially described and figured, much remains to be accomplished in the
way of restoration. Portions of _Sphenopteris bifida_, for instance, a
fern of the Lower Carboniferous rocks have been repeatedly figured; but
a beautiful specimen on the table, which exhibits what seems to be the
complete frond of the plant, will give, I doubt not, fresh ideas
respecting the general framework, if I may so speak, of this skeleton
fern, to even those best acquainted with the figures; and an elaborate
restoration of its contemporary, _Sphenopteris affinis_ (see
frontispiece) which I completed from a fine series of specimens in my
collection, will be new, as a whole, to those most familiar with this
commonest of the Burdiehouse fossils. From comparisons instituted
between minute portions of this Sphenopteris and a recent fern, it has
been held considerably to resemble a Davallia of the West Indies;
whereas it will be seen from the entire frond that it was characterized
by very striking peculiarities, exemplified, say some of our higher
botanical authorities, to whom I have submitted my restoration, by no
fern that now lives. The frond of _Davallia Canariensis_, though unlike
in its venation, greatly resembles in general outline one of the larger
pinnæ of _Sphenopteris affinis_; but these pinnæ form only a small part
of the entire frond of this Sphenopteris. It was furnished with a stout
leafless rachis, or leaf-stalk, exceedingly similar in form to that of
our common brake (_Pteris aquilina_). So completely, indeed, did it
exhibit the same club-like, slightly bent termination, the same gradual
diminution in thickness, and the same smooth surface, that one
accustomed to see this part of the bracken used as a thatch can scarce
doubt that the stipes of Sphenopteris would have served the purpose
equally well; nay, that were it still in existence to be so employed, a
roof thatched with it, on which the pinnæ and leaflets were concealed,
and only the club-like stems exposed, row above row, in the style of the
fern-thatcher, could not be distinguished, so far as form and size went,
from a roof thatched with brake. High above the club-like termination of
the rachis the stem divided into two parts, each of which, a little
higher up, also divided into two; these in turn, in at least the larger
fronds, also bifurcated; and this law of bifurcation,--a marked, mayhap
unique, peculiarity in a fern,--regulated all the larger divisions of
the frond, though its smaller pinnæ and leaflets were alternate. It was
a further peculiarity of the plant that, unlike the brake, it threw off,
ere the main divisions of its rachis took place, two pinnæ placed in the
alternate order, and of comparatively small size. The frond of
_Sphenopteris bifida_ was of a more simple form than that of its larger
congener, and not a little resembled a living fern of New Zealand,
_Coenopteris vivipara_. It was tripinnate; its secondary stems were
placed directly opposite on the midrib, but its tertiary ones in the
alternate arrangement; and its leaflets which were also alternate, were
as rectilinear and slim as mere veins, or as the thread-like leaflets of
asparagus. Like the fronds of Coenopteris when not in seed, it must
have presented the appearance of the mere macerated framework of a fern.
I need scarce remark that, independently of the scientific interest
which must attach to restorations of these early plants, they speak
powerfully to the imagination, and supply it with materials from which
to construct the vanished landscapes of the Carboniferous ages. From one
such restored fern as the two now submitted to the Association, it is
not difficult to pass in fancy to the dank slopes of the ancient land of
the Lower Coal Measures, when they waved as thickly with graceful
Sphenopteres as our existing hill sides with the common brake; and when
every breeze that rustled through the old forests bent in mimic waves
their slim flexible stems and light and graceful foliage.
In 1844, when Professor Nicol, of Marischal College, Aberdeen, appended
to his interesting "Guide to the Geology of Scotland," a list of the
Scottish fossils known at the time, he enumerated only two vegetable
species of the Scotch Oolitic system,--_Equisetum columnare_ and
_Pinites_ or _Peuce Eiggensis_; the former one of the early discoveries
of our distinguished President, Sir Roderick Murchison; the latter, of
the late Mr. William Nicol of Edinburgh. Chiefly from researches in the
Lias of Eathie, near Cromarty, and in the Oolites of Sutherland and the
Hebrides, I have been enabled to increase the list from two to rather
more than fifty species,--not a great number, certainly, regarded as the
sole representative of a flora; and yet it may be deemed comparatively
not a very small one by such as may remember, that in 1837, when Dr.
Buckland published the second edition of his "Bridgewater Treatise,"
Adolphe Brogniart had enumerated only seventy species of plants as
occurring in all the Secondary formations of Europe, from the Chalk to
the Trias inclusive. In a paper such as the present I can of course do
little more than just indicate a few of the more striking features of
the Scottish flora of the middle Secondary ages. Like that of the period
of the true Coal, it had its numerous coniferous trees. As shown by the
fossil woods of Helmsdale and Eigg, old Oolitic Scotland, like the
Scotland of three centuries ago, must have had its mighty forests of
pine;[54] and in one respect these trees seem to have more nearly
resembled those of the recent pine forests of our country than the trees
of the coniferous forests of the remote Carboniferous era. For while we
scarce ever find a cone associated with the coniferous woods of the Coal
Measures,--Lindley and Hatton never saw but one from all the English
coal fields, and Mr. Alexander Bryson of Edinburgh, only one from all
the coal fields of Scotland,--tree-cones of at least four different
species, more probably of five, are not rare in our Scottish deposits of
the Lias and Oolite. It seems not improbable that in the Carboniferous
genera Pinites, Pitus, and Anabathra, which approach but remotely to
aught that now exists, the place of the ligneous scaly cone may have
been taken, as in the junipers and the yews, by a perishable berry;
while the Pines and Araucarians of the Oolite were, like their congeners
in recent times, in reality coniferous, that is, cone-bearing trees. It
is another characteristic of these Secondary conifers, that while the
woods of the Palæozoic periods exhibit often, like those of the
tropics, none of the dense concentric lines of annual growth which mark
the reign of winter, these annual lines are scarce less strongly
impressed on the Oolitic woods than on those of Norway or of our own
country in the present day. In some of the fossil trees these yearly
rings are of great breadth; they seem to have sprung up in the rich soil
of sheltered hollows and plains, and to have increased in diameter from
half an inch to three quarters of an inch yearly; while in other trees
of the same species the yearly zones of growth are singularly
narrow,--in some instances little more than half a line in thickness.
Rooted on some exposed hill side, in a shallow and meagre soil, they
increased their diameter during the twelvemonth little more than a line
in the severer seasons, and little more than an eighth part of an inch
even when the seasons were most favorable. Further, whether the rings be
large or small, we ordinarily find them occurring in the same specimens
in groups of larger and smaller. In one of my Helmsdale specimens,
indicative generally of rapid growth, there are four contiguous annual
rings, which measure in all an inch and two twelfths across, while the
four contiguous rings immediately beside them measure only half an inch.
"If, at the present day," says a distinguished fossil botanist, "a warm
and moist summer produces a broader annual layer than a cold and dry
one, and if fossil plants exhibit such appearances as we refer in recent
plants to a diversity of summers, then it is reasonable to suppose that
a similar diversity formerly prevailed." The same reasoning is of course
as applicable to _groups_ of annual layers as to _single_ annual layers;
and may we not venture to infer from the almost invariable occurrence of
such groups in the woods of this ancient system, that that
ill-understood law of the weather which gives us in irregular
succession groups of colder and warmer seasons, and whose operation, as
Bacon tells us, was first remarked in the provinces of the Netherlands,
was as certainly in existence during the ages of the Oolite as at the
present time?
[Illustration: Fig. 130.
CONIFERS?]
[Illustration: Fig. 131.
CONIFER TWIGS.]
Twigs which exhibit the foliage of these ancient conifers seem to be
less rare in our Scotch deposits than in those of England of the same
age. My collection contains fossil sprigs, with the slim needle-like
leaves attached, of what seem to be from six to seven different
species; and it is worthy of notice, that they resemble in the group
rather the coniferæ of the southern than those of the northern
hemisphere. One sprig in my collection seems scarcely distinguishable
from that of the recent _Altingia excelsa_; another, from that of the
recent _Altingia cunninghami_. Lindley and Hutton figure in their fossil
flora a minute branch of _Dacrydium cupressinum_, in order to show how
nearly the twigs of a large tree, from fifty to a hundred feet high, may
resemble some of the "fossils referable to Lycopodiaceæ." More than one
of the Oolitic twigs in my collection are of a resembling character, and
may have belonged either to cone-bearing trees or to club mosses.
Respecting, however, the real character of at least one of the
specimens,--a minute branch from the Lias of Eathie, with the leaflets
attached,--there can be no mistake. The thicker part of the stem is in
such a state of keeping, that it presents to the microscope, in a sliced
preparation, the internal structure, and exhibits, as in recent
coniferous twigs of a year's growth, a central pith, a single ring of
reticulated tissue arranged in lines that radiate outwards, and a thin
layer of enveloping bark. Nothing, then, can be more certain than that
this ancient twig, which must be accepted as representative of the
foliage of whole forests of the Secondary ages in Scotland, formed part
of a conifer of the Lias; and the foliage of several of the other twigs,
its contemporaries, though I have failed to demonstrate their true
character in the same way, bear a scarce less coniferous aspect. The
cones of the period, from the circumstance that they are locked up in a
hard limestone that clings closely around their scales, and from the
further circumstance that the semi-calcareous lignite into which they
are resolved is softer and less tenacious than the enclosing matrix,
present, when laid open, not their outer surfaces, but mere sections of
their interior; and give, in consequence, save in their general
proportions and outline, but few specific marks by which to distinguish
them. We see, however, in some cases in these sections what would be
otherwise unseen,--the flat naked seeds lying embedded in their hollow
receptacles between the scales, and in as perfect a state of keeping as
the seeds of recent pines that had ripened only a twelvemonth ago. Had
not the vitality of seeds its limits in time, like life of all other
kinds, one might commit these perfect fossil germs to the soil, in the
hope of seeing the old extinct forests called, through their agency, a
second time into existence. Of three apparent species of cones which
occur in the Eathie Lias, the smallest seems to have resembled in size
and appearance that of the Scotch fir; the largest, which consisted from
bottom to top, as seen in section, of from nine to ten scales, appears
to have been more in the proportions of the oblong oval cones of the
spruce family; while a cone of intermediate length, but of considerably
greater breadth, assumed the rounded form of the cones of the cedar. I
have found in the same deposit what seems to be the sprig of a conifer,
with four apparently embryo cones attached to it in the alternate order.
These are rather more sessile than the young cones of the larch; but the
aspect of the whole is that of a larch twig in early summer, when the
minute and tender cones, possessed of all the beauty of flowers, first
appear along its sides.
[Illustration: Fig. 132.]
[Illustration: Fig. 133.
ZAMIA.]
[Illustration: Fig. 134.
ZAMIA.]
Among conifers of the Pine and Araucarian type we mark the first
appearance in this system, in at least Scotland, of the genus Thuja. One
of the Helmsdale plants of this genus closely resembles the common Arbor
Vitæ (_Thuja occidentalis_) of our gardens and shrubberies. It exhibits
the same numerous slim, thick-clustered branchlets, covered over by the
same minute, sessile, scale-like leaves; and so entirely reminds one of
the recent Thuja, that it seems difficult to conceive of it as the
member of a flora so ancient as that of the Oolite. But not a few of the
Oolitic plants in Scotland bear this modern aspect. The great
development of its Cycadaceæ,--an order unknown in our Coal
Measures,--also forms a prominent feature of the Oolitic flora. One of
the first known genera of this curious order,--the genus
Pterophyllum,--appears in the Trias. It distinctively marks the
commencement of the Secondary flora, and intimates that the once great
Palæozoic flora, after gradually waning throughout the Permian ages, and
becoming extinct at their close, had been succeeded by a vegetation
altogether new. At least one of the Helmsdale forms of this family is
identical with a Yorkshire species already named and figured,--_Zamia
pectinata_: a well marked Zamia which occurs in the Lias of Eathie
appears to be new. Its pinnate leaves were furnished with a strong woody
midrib, so well preserved in the rock, that it yields its internal
structure to the microscope. The ribbon-like pinnæ or leaflets were
rectilinear, retaining their full breadth until they united to the stem
at right angles, but set somewhat awry; and, like several of the recent
Zamiæ, they were striped longitudinally with cord-like lines. (Fig.
133.) Even the mode of decay of this Zamia, as shown by the abrupt
termination of its leaflets, exactly resembled that of its existing
congeners. (Fig. 134.) The withered points of the pinnæ of recent Zamiæ
drop off as if clipped across with a pair of scissors; and in fossil
fronds of this Zamia of the Lias we find exactly the same clipped-like
appearance. (Fig. 135.) Another Scotch Zamia (Fig. 136), which occurs in
the Lower Oolite of Helmsdale, resembles the Eathie one in the breadth
of its leaflets, but they are not wholly so rectilinear, diminishing
slightly towards their base of attachment; they are ranged, too, along
the stem or midrib, not at a right angle, but at an acute one; the line
of attachment is not set awry, but on the general plane of the leaf; and
the midrib itself is considerably less massive and round. A third
species from the same locality bears a general resemblance to the
latter; but the leaflets are narrower at the base, and, as the print
indicates (Fig. 136), so differently attached to the stem, that from the
pressure in the rock most of them have become detached; while yet a
fourth species (Fig. 137), very closely resembles a Zamia of the
Scarborough Oolite,--_Z. lanceolata_. The leaflets, however, contract
much more suddenly from their greatest breadth than those of
_lanceolata_, into a pseudo-footstalk; and the contraction takes place
not almost equally on both sides, as in that species, but almost
exclusively on the upper side. And so, provisionally at least, this
Helmsdale Zamia may be regarded as specifically new.
[Illustration: Fig. 135.]
[Illustration: Fig. 136.]
[Illustration: Fig. 137.]
[Illustration: Fig. 138.
CONE.]
With the leaves of the Eathie Zamia, we find, in this northern outlier
of the Lias, cones of a peculiar form, which, like the leaves
themselves, are still unfigured and undescribed, and some of which could
scarce have belonged to any coniferous tree. In one of these (Fig. 138),
the ligneous bracts or scales, narrow and long, and gradually tapering
till they assume nearly the awl-shaped form, cluster out thick from the
base and middle portions of the cone, and, like the involucral
appendages of the hazel-nut, or the sepals of the yet unfolded rose-bud,
sweep gracefully upwards to the top, where they present at their margins
minute denticulations. In another species the bracts are broader,
thinner, and more leaf-like: they rise, too, more from the base of the
cone, and less from its middle portions; so that the whole must have
resembled an enormous bud, with strong woody scales, some of which
extended from base to apex. The first described of these two species
seems to have been more decidedly a _cone_ than the other; but it is
probable that they were both connecting links between such leathern
seed-bearing flowers as we find developed in _Cycas revoluta_, and such
seed-bearing cones as we find exemplified in _Zamia pungens_. The
bud-like cone, however, does not seem to have been that of a Cycadaceous
plant, as it occupied evidently not a terminal position on the plant
that bore it, like the cones of Zamia or the flowers of Cycas, but a
lateral one, like the lateral flowers of some of the Cactus tribe.
Another class of vegetable forms, of occasional occurrence in the
Helmsdale beds, seems intermediate between the Cycadaceæ and the ferns:
at least, so near is the approach to the ordinary fern outline, while
retaining the stiff ligneous character of Zamia, that it is scarce less
difficult to determine to which of the two orders of plants such
organisms belonged, than to decide whether some of the slim graceful
sprigs of foliage that occur in the rocks beside them belonged to the
conifers or the club mosses. And I am informed by Sir Charles Lyell,
that (as some of the existing conifers bear a foliage scarce
distinguishable from that of Lycopodiaceæ), so a recently discovered
Zamia is furnished with fronds that scarce differ from those of a fern.
Even _Zamia pectinata_ may, as Sternberg remarks, have been a fern.
Lindley and Hutton place it merely provisionally among the Cycadaceæ, in
deference to the judgment of Adolphe Brogniart, and point out its
resemblance to _Polypodium pectinatum_; and a small Helmsdale frond
which I have placed beside it bears the impress of a character scarce
less equivocal. The flora of the Oolite was peculiarly a flora of
intermediate forms.
[Illustration: Fig. 139.]
[Illustration: Fig. 140.]
We recognize another characteristic of our Oolitic flora in its
simple-leaved fronds, in some of the species not a little resembling
those of the recent Scolopendrium, or Hart's-Tongue fern,--a form
regarded by Adolphe Brogniart as peculiarly characteristic of his third
period of vegetation. These simple ferns are, in the Helmsdale deposits,
of three distinct types. There is first a lanceolate leaf, from two and
a half to three inches in length, of not unfrequent occurrence, which
may have formed, however, only one of the four leaflets, united by their
pseudo-footstalks, which compose the frond of Glossopteris,--a
distinctive Oolitic genus. There is next a simple ovate lanceolate
leaf, from four to five and a half inches in length, which in form and
venation, and all save its _thrice_ greater size, not a little resembles
the leaflets of a Coal Measure neuropteris,--_N. acuminata_. And, in the
third place, there are the simple leaves that in general outline
resemble, as I have said, the fronds of the recent Hart's-Tongue fern
(_Scolopendrium vulgare_), except that their base is lanceolate, not
cordate. Of these last there are two kinds in the beds, representative
of two several species, or, as their difference in general aspect and
detail is very great, mayhap two several genera. The smaller of the two
has a slender midrib, depressed on its upper side, and flanked on each
side by a row of minute, slightly elongated protuberances, but elevated
on the under side, and flanked by rows of small but well marked grooves,
that curve outwards to the edges of the leaf. The larger resemble a
Tæniopteris of the English and Continental Oolites, save that its midrib
is more massive, its venation less at right angles with the stem, its
base more elongated, and its size much greater. Some of the Helmsdale
specimens are of gigantic proportions. From, however, a description and
figure of a plant of evidently the same genus,--a Tæniopteris of the
Virginian Oolite, given by Professor W.B. Rogers of the United
States,--I find that some of the American fronds are larger still. My
largest leaf from Helmsdale must have been nearly five inches in
breadth; and if its proportions were those of some of the smaller ones
of apparently the same species from the same locality, it must have
measured about thirty inches in length. But fragments of American leaves
have been found more than six inches in breadth, and whose length cannot
have fallen short of forty inches. The Tæniopteris, as its name bears,
is regarded as a fern. From, however, the leathern-like thickness of
some of the Sutherland specimens,--from the great massiveness of their
midrib,--from the rectilinear simplicity of their fibres,--and, withal,
from, in some instances, their great size,--I am much disposed to
believe that in our Scotch, mayhap also in the American species, it may
have been the frond of some simple-leaved Cycas or Zamia. But the point
is one which it must be left for the future satisfactorily to settle;
though provisionally I may be permitted to regard these leaves as
belonging to some Cycadaceous plant, whose fronds, in their venation
and form, resembled the simple fronds of Scolopendrium, just as the
leaves of some of its congeners resembled the fronds of the pinnate
ferns.
[Illustration: Fig. 141.]
[Illustration: Fig. 142.]
I have already referred to the close resemblance which certain
Cycadaceous genera bear to certain of the fern family. In at least two
species of Pterophyllum,--_P. comptum_ and _P. minus_,--the divisions of
the leaflets seem little else than accidental rents in a simple frond;
in _P. Nelsoni_ they are apparently _nothing_ more; and similar
divisions, evidently, however, the effect of accident, and less rounded
at their extremities than in at least _P. comptum_, we find exhibited by
some of the Helmsdale specimens of Tæniopteris (See Fig. 142, p. 488.)
But whatever the nature of these simple fronds, they seem to impart much
of its peculiar character, all the world over, to the flora of the
Oolitic ages.
[Illustration: Fig. 143.
PECOPTERIS OBTUSIFOLIA.]
[Illustration: Fig. 144.]
[Illustration: Fig. 145.
PACHYPTERIS.]
The compound ferns of the formation are numerous, and at least
proportionally a considerable part of them seem identical in species
with those of the Oolite of England. (See Fig. 143.) Among these there
occur _Pecopteris Whitbiensis_, _Pecopteris obtusifolia_, _Pecopteris
insignis_,--all well marked English species; with several others. It
has, besides, its apparent ferns, that seem to be new--(Fig. 144)--that
are at least not figured in any of the fossil floras to which I have
access,--(Fig. 145),--such as a well defined Pachypteris, with leaflets
broader and rounder than the typical _P. lanceolata_, and a much stouter
midrib; a minute Sphenopteris too, and what seems to be a Phlebopteris,
somewhat resembling _P. propinqua_, but greatly more massive in its
general proportions. The equisetacea we find represented in the Brora
deposits by _Equisetum columnare_,--a plant the broken remains of which
occur in great abundance, and which, as was remarked by our President
many years ago, in his paper on the Sutherlandshire Oolite, must have
entered largely into the composition of the bed of lignite known as the
Brora Coal. We find associated with it what seems to be the last of the
Calamites,--_Calamites arenaceus_,--a name, however, which seems to have
been bestowed both on this Oolitic plant and a resembling Carboniferous
species. The deposit has also its Lycopodites, though, from their
resemblance in foliage to the conifers, there exists that difficulty in
drawing the line between them to which I have already adverted. One of
these, however, so exactly resembles a lycopodite of both the Virginian
and Yorkshire Oolite,--_L. uncifolius_,--that I cannot avoid regarding
it as specifically identical; and it seems more than doubtful whether
the stem which I have placed among the conifers is not a lycopodite
also. It exhibits not only the general outline of the true club moss,
but, like the fossil club mosses too, it wants that degree of
ligniferous body in the rock which the coniferous fossils almost always
possess. Yet another of the organisms of the deposit seems to have been
either a lycopodite or a fern. Its leaflets are exceedingly minute, and
set alternately on a stem slender as a hair,--circumstances in which it
resembles some of the tiny lycopodites of the tropics, such as
_Lycopodium apodium_. I must mention, however, that the larger plant of
the same beds which I have placed beside it, and which resembles it so
closely that my engraver finds it difficult to indicate any other
difference between them than that of size, appears to be a true fern,
not a lycopodium. To yet another vegetable organism of the system,--an
organism which must be regarded, if I do not mistake its character, as
at once very interesting and extraordinary, occurring as it does so low
in the scale, and bearing an antiquity so high,--I shall advert, after a
preliminary remark on a general characteristic of the flora to which it
belongs, but to which it seems to furnish a striking exception.
[Illustration: Fig. 146.
PHLEBOPTERIS.]
[Illustration: Fig. 147.]
[Illustration: Fig. 148.]
From the disappearance of many of those anomalous types of the Coal
Measures which so puzzle the botanist, and the extensive introduction of
types that still exist, we can better conceive of the general features
and relations of the flora of the Oolite than of those of the earlier
floras. And yet the general result at which we arrive may be found not
without its bearing on the older vegetations also. Throughout almost all
the families of this Oolitic flora, there seems to have run a curious
bond of relationship, which, like those ties which bound together some
of the old clans of our country, united them, high and low, into one
great sept, and conferred upon them a certain wonderful unity of
character and appearance. Let us assume the ferns as our central group.
Though less abundant than in the earlier creation of the Carboniferous
system, they seem to have occupied, judging from their remains, very
considerable space in the Oolitic vegetation; and with the ferns there
were associated in great abundance the two prevailing families of the
Pterides,--Equiseta and Lycopodia,--plants which, in most of our modern
treatises on the ferns proper, take their place as the fern allies. (See
Fig. 148.) Let us place these along two of the sides of a pentagon,--the
Lycopodia on the right side of the ferns, the Equiseta on the left;
further, let us occupy the two remaining sides of the figure by the
Coniferæ and the Cycadaceæ,--placing the Coniferæ on the side next the
Lycopodia, and the Cycadaceæ, as the last added keystone of the
erection, between these and the Equiseta. And now, let us consider how
very curious the links are which give a wonderful unity to the whole. We
still find great difficulty in distinguishing between the foliage of
some of even the existing club mosses and the conifers; and the ancient
Lepidodendra are very generally recognized as of a type intermediate
between the two. Similar intermediate types, exemplified by extinct
families, united the conifers and the ferns. The analogy of _Kirchneria_
with the _Thinnfeldia_, says Dr. Braun, is very remarkable,
notwithstanding that the former is a fern, and that the latter is ranked
among conifers. The points of resemblance borne by the conifers to the
huge Equiseta of the Oolitic period seem to have been equally striking.
The pores which traverse longitudinally the channelled grooves by which
the stems of our recent Equiseta are so delicately fluted, are said
considerably more to resemble the discs of pines and araucarians than
ordinary stomata. Mr. Francis does not hesitate to say, in his work on
British Ferns, that the relation of this special family to the Coniferæ
is so strong, both in external and internal structure, that it is not
without some hesitation he places them among the fern allies; and it has
been ascertained by Mr. Dawes, in his researches regarding the calamite,
that in its internal structure this apparent representative of Equiseta
in the earlier ages of the world united "a network of quadrangular
tissue similar to that of Coniferæ to other quadrangular cells arranged
in perpendicular series," like the cells of plants of a humbler order.
The relations of the Cycadacean order to ferns on the one hand, and to
the Coniferæ on the other, are equally well marked. As in the ferns, the
venation of its fronds is circinate, or scroll-like,--they have in
several respects a resembling structure,--in at least one recent species
they have a nearly identical form; and fronds of this fern-like type
seem to have been comparatively common during the times of the Oolite.
On the other hand, the Cycadaceæ manifest close relations to the
conifers. Both have their seeds originally naked; both are cone-bearing;
both possess discs on the sides of their cellules; and in both, in the
transverse section, these cellules are subhexagonal, and radiate from a
centre. Such were the very curious relations that united into one great
sept the prevailing members of the Oolitic flora; and similar bonds of
connection seem to have existed in the floras of the still earlier ages.
[Illustration: Fig. 149.
IMBRICATED STEM.
(_Helmsdale._)]
[Illustration: Fig. 150.
(_Helmsdale._)]
[Illustration: Fig. 151.]
In the Oolite of Scotland I have, however, at length found trace of a
vegetable organism that _seems_ to have lain, if I may so express
myself, outside the pentagon, and was not a member of any of the great
families which it comprised. (See Fig. 151.) I succeeded about four
years ago in disinterring from the limestone of Helmsdale what
_appears_ to be a true dicotyledonous leaf, with the fragment of another
leaf, which I at first supposed might have belonged to a plant of the
same great class, but which I now find might have been a portion of a
fern. When _Phlebopteris Phillipsii_ was first detected in the Oolite of
Yorkshire, Lindley and Hatton, regarding it as dicotyledonous,
originated their term Dictyophillum as a general one for all such
leaves. But it has since been assigned to a greatly lower order,--the
ferns; and Sir Charles Lyell has kindly shown me that an exotic fern of
the present day exhibits exactly such a reticulated style of venation as
my Helmsdale fragment. (See Fig. 152, p. 497.) The other leaf, however,
though also fragmentary, and but indifferently preserved, seems to be
decidedly marked by the dicotyledonous character; and so I continue to
regard it, provisionally at least, as one of the first precursors in
Scotland of our great forest trees, and of so many of our flowering and
fruit-bearing plants, and as apparently occupying the same relative
place in advance of its contemporaries as that occupied by the conifer
of the Old Red Sandstone in advance of the ferns and Lycopodaceæ with
which I found it associated. In the arrangement of its larger veins the
better preserved Oolitic leaf somewhat resembles that of the buckthorn;
but its state of keeping is such that it has failed to leave its
exterior outline in the stone.
[Illustration: Fig. 152.]
One or two general remarks, in conclusion, on the Oolite flora of
Scotland may be permitted me by the Association. In its aspect as a
whole it greatly resembles the Oolite flora of Virginia, though
separated in space from the locality in which the latter occurs by a
distance of nearly four thousand miles. There are several species of
plants common to both, such as _Equisetum columnare_, _Calamites
arenaceus_, _Pecopteris Whitbiensis_, _Lycopodites uncifolius_, and
apparently _Tæniopteris magnifolia_; both, too, manifest the great
abundance in which they were developed of old by the beds of coal into
which their remains have been converted. The coal of the Virginia Oolite
has been profitably wrought for many years: it is stated by Sir Charles
Lyell, who carefully examined the deposit, and has given as the results
of his observation in his second series of Travels in the United States,
that the annual quantity taken from the Oolitic pits by Philadelphia
alone amounted to ten thousand tons; and though, on the other hand, the
Sutherlandshire deposit has never been profitably wrought, it has been
at least wrought more extensively than any other in the British Oolite.
The seam of Brora, varying from three feet three to three feet eight
inches in thickness, furnished, says Sir Roderick Murchison, between the
years 1814 and 1826, no less than seventy thousand tons of coal. Such is
its extent, too, that nearly thirty miles from the pit's mouth (in
Ross-shire under the Northern Sutor) I have found it still existing,
though in diminished proportions, as a decided coal seam, which it must
have taken no small amount of vegetable matter to form. And almost on
the other side of the world, nearly five thousand miles from the
Sutherland beds, and more than eight thousand miles from the Carolina
ones, the same Oolitic flora again appears, associated with beds of
coal. At Nagpur in Central India the Oolitic Sandstones abound in simple
fronded ferns, such us Tæniopteris and Glossopteris, and has its
Zamites, its coniferous leaves, and its equisetaceæ.
Compared with existing floras, that of our Scottish Oolite seems to have
most nearly resembled the flora of New Zealand,--a flora remarkable for
the great abundance of its ferns, and its vast forests of coniferous
trees, that retain at all seasons their coverings of acicular spiky
leaves. It is to this flora that _Dacrydium cupressinum_,--so like a
club moss in its foliage,--belongs; and _Podocarpus ferrugineus_,--a
tree which more closely resembles in its foliage the Eathie conifer,
save that its spiky leaves are somewhat narrower and longer than any
other with which I am acquainted. About two thirds of the plants which
cover the plains, or rise on the hill-sides of that country, are
cryptogamic, consisting mainly of ferns and their allies; and it is a
curious circumstance,--which was, however, not without precedent in the
merely physical conditions of the Oolitic flora of Scotland,--that so
shallow is the soil even where its greatest forests have sprung up, and
so immediately does the rock lie below, that the central axes of the
trees do not elongate downwards into a tap, but throw out horizontally
on every side a thick network of roots, which rises so high over the
surface as to render walking through the woods a difficult and very
fatiguing exercise. The flora of the Oolite, like that of New Zealand,
seems to have been in large part cryptogamic, consisting of ferns and
the allied horse-tail and club moss families. Its forests seem to have
contained only cone-bearing trees; at least among the many thousand
specimens of its fossil woods which have been examined, no tissue of the
true, dicotyledonous character has yet been found; and with the
exception of the leaves just described, all those yet found in the
System, which could have belonged to true trees, are of the acicular
form common to the Coniferæ, and show in their dense ligneous structure
that they were persistent, not deciduous. Nor is there evidence wanting
that many of the Coniferæ of the period grew in so shallow a soil, that
their tap-roots were flattened and bent backwards, and they were left to
derive their sole support, like the trees of the New Zealand forests,
from such of their roots as shot out horizontally. We even know the
nature of the rock upon which they rested. As shown by fragments still
locked up among the interstices of their petrified roots, it was an Old
Red flagstone similar to that of Caithness in the neighborhood of Wick
and Thurso, and containing the same fossil remains. In the water-rolled
pebbles of the Conglomerate of Helmsdale and Port Gower,--pebbles
encrusted by Oolitic corals, and enclosed in a calcareous paste,
containing Oolitic belemnites and astreæ,--I have found the well marked
fishes and fucoids of the Old Red Sandstone. As shown by the appearance
of the rounded masses in which these lay, they must have presented as
ancient an appearance in the times of the Lower Oolite as they do now;
and the glimpse which they lent of so remote an antiquity, through the
medium of an antiquity which, save for the comparison which they
furnished the means of instituting, might be well deemed superlatively
remote, I have felt singularly awe-inspiring and impressive. Macaulay
anticipates a time when the traveller from some distant land shall take
his stand on a broken arch of London Bridge to survey the ruins of St.
Paul's. In disinterring from amid the antique remains of the Oolite the
immensely more antique remains of the Old Red Sandstone, I have felt as
such a traveller would feel if, on setting himself to dig among the
scattered heaps for memorials of the ruined city, he had fallen on what
had been once the Assyrian Gallery of the British Museum, and had found
mingling with the antiquities of perished London the greatly older and
more venerable antiquities of Nineveh or of Babylon. The land of the
Oolite in this northern locality must have been covered by a soil
which,--except that from a lack of the boulder clays it must have been
poorer and shallower,--must have not a little resembled that of the
lower plains of Cromarty, Caithness, and Eastern Ross. And on this
Palæozoic platform, long exposed, as the Oolitic Conglomerates
abundantly testify, to denuding and disintegrating agencies,--a platform
beaten by the surf where it descended to the sea level, and washed in
the interior by rivers, with here a tall hill or abrupt precipice, and
there a flat plain or sluggish morass,--there grew vast forests of
cone-bearing trees, tangled thickets of gigantic equisetaceæ, numerous
forms of Cycas and Zamia, and wide-rolling seas of fern, amid whose open
spaces club mosses of extinct tribes sent forth their long, creeping
stems, spiky and dry, and thickly mottled with pseudo-spore-bearing
catkins.
The curtain drops over this ancient flora of the Oolite in Scotland; and
when, long after, there is a corner of the thick enveloping screen
withdrawn, and we catch a partial glimpse of one of the old Tertiary
forests of our country, all is new. Trees of the high dicotyledonous
class, allied to the plane and the buckthorn, prevail in the landscape,
intermingled, however, with dingy funereal yews; and the ferns and
equisetæ that rise in the darker openings of the wood approach to the
existing type. And yet, though _eons_ of the past eternity have elapsed
since we looked out upon Cycas and Zamia, and the last of the Calamites,
the time is still early, and long ages must lapse ere man shall arise
out of the dust, to keep and to dress fields waving with the productions
of yet another and different flora, and to busy himself with all the
labor which he taketh under the sun. Our country, in this Tertiary time,
has still its great outbursts of molten matter, that bury in fiery
deluges many feet in depth, and many square miles in extent, the debris
of wide tracts of woodland and marsh; and the basaltic columns still
form in its great lava bed; and ever and anon, as the volcanic agencies
awake, clouds of ashes darken the heavens, and cover up the landscape as
if with accumulated drifts of a protracted snow storm. Who shall
declare what, throughout those long ages, the history of creation has
been? We see at wide intervals the mere fragments of successive floras;
but know not how what seem the blank interspaces were filled, or how, as
extinction overtook in succession one tribe of existences after another,
and species, like individuals, yielded to the great law of death, yet
other species were brought to the birth, and ushered upon the scene, and
the chain of being was maintained unbroken. We see only detached bits of
that green web which has covered our earth ever since the dry land first
appeared; but the web itself seems to have been continuous throughout
all time; though ever as breadth after breadth issued from the creative
loom, the pattern has altered, and the sculpturesque and graceful forms
that illustrated its first beginnings and its middle spaces have yielded
to flowers of richer color and blow, and fruits of fairer shade and
outline; and for gigantic club mosses stretching forth their hirsute
arms, goodly trees of the Lord have expanded their great boughs; and for
the barren fern and the calamite, clustering in thickets beside the
waters, or spreading on flowerless hill slopes, luxuriant orchards have
yielded their ruddy flush, and rich harvests their golden gleam.
THE END.
FOOTNOTES:
[1] The Prayer will be found at the end of these Memorials.
[2] The same revolver proved to be the instrument of death to another
person, two days after. The circumstances are thus related in the
_Edinburgh Witness_ of December 27:--
"A most melancholy event, arising out of the following circumstances,
occurred yesterday in the shop of Mr. Thomson, gunmaker. In the
beginning of July, last year, Mr. Hugh Miller bought a six-shot
revolving chamber pistol, size of ball ninety-two to the pound, from the
late firm of Messrs. Alexander Thomson & Son, gunmakers, 16 Union Place.
A few days after, he called and said he thought it a little stiff in its
workings, and got it made to revolve more readily. The pistol has not
been seen by Mr. Thomson since then; but in his absence a few minutes at
dinner yesterday, Professor Miller called about twenty minutes from two,
and asked Mr. Thomson's foreman how many of the six shots had been
fired. He added, 'Mind, it is loaded.' The foreman, instead of removing
the breech or chamber to examine it, bad incautiously turned the pistol
entire towards his own person, and lifting up the hammer with his
fingers, while he counted the remaining loaded chambers, he must have
slipped his fingers while the pistol was turned to his own head. It
exploded, and the ball lodging in the angle of his right eye, he fell
back a lifeless corpse. The pistol is a bolted one, which permits of
being carried loaded with perfect safety. Having been wet internally,
rust may have stopped the action of the bolt. It is a singular fact that
Hugh Miller dropped the pistol into the bath, where it remained for
several hours. This may account for the apparent incaution of Mr.
Thomson's foreman."
[3] See _ante_, p. 9.
[4] The horizontal lines in this diagram indicate the divisions of the
various geologic systems; the vertical lines the sweep of the various
classes or sub-classes of plants across the geologic scale, with, so far
as has yet been ascertained, the place of their first appearance in
creation; while the double line of type below shows in what degree the
order of their occurrence agrees with the arrangement of the botanist.
The single point of difference indicated by the diagram between the
order of occurrence and that of arrangement, viz., the transposition of
the gymnogenous and monocotyledonous classes, must be regarded as purely
provisional. It is definitely ascertained that the Lower Old Red
Sandstone has its coniferous wood, but not yet definitely ascertained
that it has its true monocotyledonous plants; though indications are not
awanting that the latter were introduced upon the scene at least as
early as the pines or araucarians; and the chance discovery of some
fossil in a sufficiently good state of keeping to determine the point
may, of course, at once retranspose the transposition, and bring into
complete correspondence the geologic and botanic arrangements.
[5] The horizontal lines of the diagram here indicate, as in Fig. 1, the
divisions of the several geologic systems; the vertical lines represent
the leading divisions and classes of animals, and, as shown by the
formations in which their earliest known remains occur, the probable
period of their first appearance in creation; while the double line of
text below exhibits the complete correspondence which obtains between
their occurrence, in nature and the Cuvierian arrangement. The line
representative of the Radiata ought perhaps to have been elevated a
little higher than either of its two neighbors.
[6] Fig. 14, Neuropteris Loshii. Fig. 15, Neuropteris gigantea. Fig. 16,
Neuropteris acuminata. Fig. 17, Sphenopteris affinis. Fig. 18,
Pecopteris heterophylla. Fig. 19, Sphenopteris dilitata.
[7] Fig. 21, _r a_, Rachis, greatly thickened towards its base by
numerous ærial roots, shot downwards to the soil, and which closely
cover the stem.
[8] Fig. 22, _m_, Cellular tissue of the centre of rachis; _d_, similar
tissue of the circumference; _f_, _v_, darkly-colored woody fibres of
great strength, the "internal buttresses" of the illustration; _e_, the
outer cortical portion formed by the bases of the leaves.
[9] Fig. 23, Branching stem, with bark and leaves. Fig. 24. Extremity of
branch. Fig. 25, Extremity of another branch, with indication of
cone-like receptacle of spores or seed.
[10] No true fossil palms have yet been detected in the great Oolitic
and Wealden systems, though they certainly occur in the Carboniferous
and Permian rocks, and are comparatively common in the earlier and
middle Tertiary formations. Much cannot be founded on merely negative
evidence; but it would be certainly a curious circumstance should it be
found that this graceful family, first ushered into being some time in
the later Palæozoic periods, was withdrawn from creation during the
Middle ages of the earth's history, to be again introduced in greatly
more than the earlier proportions during the Tertiary and recent
periods.
[11] Leaf of a tree allied to the maple.
[12] Leaf of a tree allied to the elm.
[13] Here, as in the former diagrams (Figs. 1 and 4), the horizontal
lines represent the divisions of the great geologic systems; while the
vertical lines indicate the sweep of the several orders of fishes across
the scale, and the periods, so far as has yet been determined, of their
first occurrence in creation.
[14] Some of these _dragons_ of the Secondary ages were of very
considerable size. The wings of a Pterodactyle of the Chalk, in the
possession of Mr. Bowerbank, must have had a spread of about eighteen
feet; those of a recently discovered Pterodactyle of the Greensand, a
spread of not less than twenty-seven feet. The _Lammer-geyer_ of the
Alps has an extent of wing of but from ten to eleven feet; while that of
the great Condor of the Andes, the largest of flying birds, does not
exceed twelve feet.
[15] _a_, Palæotherium magnum. _b_, Palæotherium minus. _c_,
Anoplotherium commune.
[16] It will be seen that there is no attempt made in this lecture to
represent the great Palæozoic division as characterized _throughout its
entire extent_ by a luxuriant flora. It is, on the contrary, expressly
stated here, that the "plants of its earlier and terminal formations
(_i.e._ those of the Silurian, Old Red, and Permian Systems) were _few
and small_," and that "it was _only during the protracted eons of the
carboniferous period that they received their amazing development,
unequalled in any previous or succeeding time_." Being thus express in
my limitation, I think I have just cause of complaint against any one
who represents me us unfairly laboring, in this very composition, to
make it be believed that the _whole_ Palæozoic period was characterized
by a gorgeous flora; and as thus sophistically generalizing in the first
instance, in order to make a fallacious use of the generalization in the
second, with the intention of misleading non-geologic readers. Such,
however, as may be seen from the following extracts from the
"Proceedings of the Academy of Natural Science at Philadelphia," is the
charge preferred against me by a citizen of the United States.
"Mr. William Parker Foulke asked the attention of the Society to a
lecture by Mr. Hugh Miller, recently republished in the United States
under the title of 'The Two Records, Mosaic and Geological,' and made
some remarks upon the importance of maintaining a careful scrutiny of
the logic of the natural sciences.... Mr. Miller teaches that, in the
attempt to reconcile the two 'records,' there are only three periods to
be accounted for by the geologist, viz. 'the period of _plants_; the
period of _great sea monsters and creeping things_; and the period of
_cattle and beasts of the earth_;' and that the first of these periods
is represented by the rocks grouped under the term _Palæozoic_, and is
distinguished from the _Secondary_ and _Tertiary_ chiefly by its
gorgeous flora; and that the geological evidence is so complete as to be
patent to all, that the first great period of organized being was, as
described in the Mosaic record, peculiarly a period of herbs and trees,
yielding seed after their kind. The general reader, not familiar with
the details of geological arrangement, could not fail to infer from such
a statement, used for such a purpose, that the Palæozoic rocks are
regarded by geologists as forming one group representative of one
period, which can properly be said to be distinguished as a _whole_ by
its gorgeous flora; and that it is properly so distinguished _for the
argument in question_. It was familiar to the Academy, as well as to Mr.
Miller, that from the _carboniferous_ rocks downward (backward in order
of time), there have been discriminated a large number of periods,
differing from one another in mineral and in organic remains; and that
the proportion of the _carboniferous_ era to the whole series is small,
whether we regard the thickness of its deposits or its conjectural
chronology. It in only of this _carboniferous_ era, _the latest of this
series_, that the author's remarks could be true; and even of this, if
taken for the entire surface of the earth, it could not be truly
asserted that 'the evidence is so complete as to be patent to all,' that
the quantity of its vegetable products distinguishes it from the earth's
surface during the era in which we live. To confound by implication all
this periods termed Palæozoic, so as to apply to them as a whole what
could be true, if at all, only of the _carboniferous_ period, is a
fallacious use of a generalization _made for a purpose_, and upon a
principle not properly available for the writer's argument," &c. So far
the "Proceedings" of the Academy.
This, surely, is very much the reverse of fair. I, however, refer the
matter, without note or comment (so far at least as it involves the
question whether Mr. Foulke has not, in the face of the most express
statement on my part, wholly misrepresented me), to the judgment of
candid and intelligent readers on both sides of the Atlantic.
I know not that I should recognize Mr. Foulke as entitled, after such a
display, to be dealt with simply as the member of a learned society who
differs from me on a scientific question; nor does his reference to the
"carboniferous era" as "the _latest_ of the" Palæozoic "series," and his
apparent unacquaintance with that Permian period, in reality the
terminal one of the division during which the Palæozoic forms seem to
have gradually died away, in order to give place to those of the
Secondary division, inspire any very high respect for his acquirements
as a geologist. Waiving, however, the legitimacy of his claim, I may be
permitted to repeat, for the further information of the non-geological
reader, that the _carboniferous_ formations, _wherever they have yet
been detected_, justify, in the amazing abundance of their carbonized
vegetable organisms, the name which they bear. Mr. Foulke, in three
short sentences, uses the terms "carboniferous era," "carboniferous
rocks," "carboniferous period," four several times; and these terms are
derived from the predominating amount of carbon (elaborated of old by
the plants of the period) which occurs in its several formations. The
very language which he has to employ is of itself a confirmation of the
statement which he challenges. For so "patent" is this _carboniferous_
character of the system, that it has given to it its universally
accepted designation,--the verbal sign by which it is represented
wherever it is known. Mr. F. states, that "if taken for the entire
surface of the earth," it cannot be truly asserted that the
carboniferous flora preponderated over that of the present time, or, at
least, that its preponderance could not be regarded as "patent to all,"
The statement admits of so many different meanings, that I know not
whether I shall succeed in replying to the special meaning intended by
Mr. Foulke. There are no doubt carboniferous deposits on the earth's
surface still unknown to the geologist, the evidence of which on the
point must be regarded, in consequence, not as "patent to all," but as
_nil_. They are witnesses absent from court, whose testimony has not yet
been tendered. But equally certain it is, I repeat, that wherever
carboniferous formations _have_ been discovered and examined, they have
been found to bear the unique characteristic to which the system owes
its name,--they have been found charged with the carbon, existing
usually as great beds of coal, which was elaborated of old by its
unrivalled flora from the elements. And as this evidence is certain and
positive, no one would be entitled to set off against it, as of equal
weight, the merely negative evidence of some one or two deposits of the
carboniferous age that did not bear the carboniferous character, even
were such known to exist; far less is anyone entitled to set off against
it the _possibly_ negative evidence of deposits of the carboniferous age
not yet discovered nor examined; for that would be simply to set off
against good positive evidence, what is no evidence at all. It would be
to set off the _possible_ evidence of the absent witnesses, not yet
precognosced in the case, against the express declarations of the
witnesses already examined, and strong on the positive side.
Surely an American, before appealing, in a question of this kind, to the
bare possibility of the existence somewhere or other of barely negative
evidence, ought to have bethought him of the very extraordinary positive
evidence furnished by the carboniferous deposits of his own great
country. The coal fields of Britain and the European continent had been
wrought for ages ere those of North America were known, and for ages
more after it had been but ascertained that the New, like the Old World,
has its Coal Measures. And during the latter period the _argument_ of
Mr. Foulke might have been employed, just as now, and some member of a
learned society might have urged that, though the coal fields of Europe
bore evidence to the former existence of a singularly luxuriant flora,
beyond comparison more vast than the European one of the present day,
the same could not be predicated of the American coal fields, whose
carbonized remains _might_ be found representative of a flora which had
been at least not more largely developed than that existing American
flora to which the great western forests belong. Now, however, the time
for any such argument has gone by; the American coal fields have been
carefully explored; and what is the result? The geologist has come to
know, that even the mighty forests of America are inconsiderable,
compared with its deposits of coal; nay, that all its forests gathered
into one heap would fail to furnish the materials of a single coal seam
equal to that of Pittsburg; and that centuries after all its thick woods
shall have disappeared before the axe, and it shall have come to present
the comparatively bare, unwooded aspect of the long civilized countries
of Southern Europe, it will continue to derive the elements of its
commercial greatness, and the cheerful blaze of its many millions of
domestic hearths, from the unprecedentedly luxurious flora of the old
carboniferous ages. Truly, very wonderful are the coal fields of
Northern America! If geologists inferred, as they well might, that the
extinct flora which had originated the European coal vastly outrivalled
in luxuriance that of the existing time, what shall be said of that
flora of the same age which originated the coal deposits of Nova Scotia
and the United States,--deposits _twenty times as great_ as all those of
all Europe put together!
[17] Such is also the view taken by the author of a recently published
work, "The Genesis of the Earth and of Man." "Christian philosophers
have been compelled to acknowledge," says this writer, "that the Mosaic
account of creation is only reconcileable with demonstrated facts, by
its being regarded as a record of _appearances_; and if so, to vindicate
the truth of God, we must consider it, so far as the acts are concerned,
as the relation of a revelation to the _sight_, which was sufficient for
all its purposes, rather than as one in words; though the words are
perfectly true as describing the revelation itself, and the revelation
is equally true as showing man the principal phenomena which he would
have seen had it been possible for him to be a witness of the events.
Further, if we view the narrative as the description of a series of
visions, while we find it to be perfectly reconcileable with the
statement in other parts of Scripture, that in six days the Lord made
heaven and earth, we remove, with other difficulties, the only strong
objection to the opinion of those who regard the 'six days' as periods
of undeflnable duration, and who may even believe that we are now in the
'seventh day,'--the day of rest or of cessation from the work of
creation. Certainly, 'the day of God,' and 'the day of the Lord,' and
the 'thousand two hundred and threescore days,' of the Revelation of St.
John, and the 'seventy weeks' in the Prophecy of Daniel, are not to be
understood in their primary and natural senses," &c., &c.
[18] "For in six days the Lord made heaven and earth, the sea, and all
that in them is, and rested the seventh day: wherefore the Lord blessed
the Sabbath day, and hallowed it."
[19] Forbes and Hanley enumerate one hundred and sixty bivalves, and two
hundred and thirty-two univalves,--in all three hundred and ninety-two
species, as the only known shell-bearing molluscs of the existing
British seas.
[20] Principles of Zoology: touching the Structure, Development,
Distribution, and Natural Arrangement of the Races of Animals, living
and extinct. With numerous Illustrations. For the Use of Schools and
Colleges. Part I., "Comparative Physiology." By Louis Agassiz and
Augustus A. Gould. Boston: Gould & Lincoln.
[21] _a_, Articulating surface of joint. _b_, Fragment of column,
exhibiting laterally the tooth processes, so fitted into each other as
to admit of flexure without risk of dislocation. The uppermost joint
shows two lateral cavities for the articulation of auxiliary arms.
[22] Perhaps one strengthening principle more might be enumerated as
occurring in this curious piece of mechanism. In the layer of the nether
plate, the fibres, instead of being laid in parallel lines, like the
threads in the moleskin of my illustration, seem to be _felted_
together,--an arrangement which must have added considerably to their
coherency and powers of resistance.
[23] Fig. 102, Clymenia Sedwicki; Fig. 103, Gyroceras Eifelensis; Fig.
104, Cirrus Goldfussii.
[24] Berosus, Hieronymus, Mnaseas, Nicolaus, Manetho, Mochus, and
Hestæus.
[25] See Cory's "Ancient Fragments."
[26] As was common in Bible illustrations published in our own country a
century and a half ago, the old Greek artist has introduced into his
medal two points of time. Two of the figures represent _Noe_ and his
wife quitting the ark; while the other two exhibit them as seated within
it. An English print of the death of Abel, now before me, which dates a
little after the times of the Revolution, shows, on the same principle,
the two brothers, represented by four figures,--two of these quietly
offering up their respective sacrifices in the background, and the other
two grappling in deadly warfare in front.
[27] "In preparing the 'Horæ Biblicæ Quotidianæ,' he [Dr. Chalmers] had
beside him, for use and reference, the Concordance, the Pictorial Bible,
Poole's Synopsis, Henry's Commentary, and Robertson's Researches in
Palestine. These constituted what he called his Biblical Library.
'There,' said he to a friend, pointing, as he spoke, to the above named
volumes as they lay together on his library table, with a volume of the
'Quotidianæ,' in which he had just been writing, lying open beside
them,--'these are the books I use: all that is Biblical is
there.'"--_Dr. Hanna's Preface to "Daily Scripture Readings."_
[28] The raven is said to live for more than a hundred years. I am,
however, not prepared to say that it was the same pair of birds that
used, year after year, to build on the same rock-shelf among the
precipices of Navity, from the times of my great-grandfather's boyhood
to those of my own.
[29] The following estimate of the air-breathing vertebrates (that of
the "Physical Atlas," second edition, 1856) may be regarded as the
latest. It will he seen that it does not include the cetacea or the
seals:--
SPECIES.
Quadrumana 170
Marsupialia 123
Edentata 28
Pachydermata 39
Terrestrial Carnivora 514
Rodentia 604
Ruminantia 180
---- 1658
Birds 6266
Reptiles 657
Turtles 8}
Sea Snakes 7} 15
---- 642
Great as is this number of animals, compared with those known a century
ago, there are indications that the list is to be increased rather than
diminished. Even by the latest European authorities the reindeer is
represented as consisting of but a single species, common to the
sub-arctic regions of both the Old and New Worlds; whereas in the
"Canadian Naturalist" for 1856 I find it stated, on what seems to be
competent authority, that America has its two species of reindeer, and
that they both differ from the European species.
[30] If I do not introduce here the argument founded on the great age of
certain gigantic trees, such as the Baobab of intertropical Africa, or
the Taxodium of South America, it is not because I have any reason to
challenge the estimates of Adamson or Candolle. The one tree may have
lived its five thousand, the other its six thousand, years; but as the
grounds have been disputed on which the calculations respecting their
vast age have been founded, and as they cannot be reëxamined anew by the
reader, I wholly omit the evidence, in the general question, which they
have been supposed to furnish.
[31] The following excellent remarks on the economy of miracle, by
Chalmers, bear very directly on this subject:--"It is remarkable that
God is sparing of miracles, and seems to prefer the ordinary processes
of nature, if equally effectual for the accomplishment of his purposes.
He might have saved Noah and his family by miracles; but he is not
prodigal of these, and so he appointed that an ark should be made to
bear up the living cargo which was to be kept alive on the surface of
the waters; and not only so, but he respects the laws of the animal
physiology, as he did those of hydrostatics, in that he put them by
pairs into the ark, male and female, to secure their transmission to
after ages, and food was stored up to sustain them during their long
confinement. In short, he dispenses with miracles when these are not
requisite for the fulfilment of his ends; and he never dispenses with
the ordinary means when these are fitted, and at the same time
sufficient, for the occasion."--_Daily Scripture Readings_, vol. i. p.
10.
[32] For a brief but masterly view of these ancient cosmogonies, see the
Rev. D. Macdonald's "Creation and the Fall." Edinburgh: Constable & Co.
[33]
1. The great surrounding oceans.
2. Caspian Sea.
3. River Phison.
4-4. Points of the Compass.
5. Mediterranean Sea.
6. Red Sea.
7-8. Persian Gulf, with the rivers Tigris and Euphrates.
9. River Gihon.
[34]
1. The sun Occident.
2. The sun orient.
3. The Heavens.
4. Great mountain behind which the sun is hidden when it is night.
5. The Mediterranean Sea.
6. Red Sea.
7. Persian Gulf.
8. Garden of Eden.
9. Great surrounding ocean
10. The Creator looking down upon his work, and seeing that all was good.