THE OLD RED SANDSTONE.
“The fishes of the sea shall declare unto thee.”—JOB.
Lord Bacon remarks, “Some men think that the gratification of curiosity
is the end of knowledge, some the love of fame, some the pleasure of
dispute, and some the necessity of supporting themselves by knowledge;
but the real use of all knowledge is this, that we should dedicate that
reason which was given us by God to the use and advantage of man.” The
historian of the old red sandstone, Hugh Miller, to whose researches not
only we, but such men as Murchison, Lyell, Ansted, Agassiz and others,
are so exclusively indebted, is a philosopher in this last category. He
does not hesitate to tell us, how, as a Cromarty quarryman “twenty years
ago,” he commenced a “life of labour and restraint,” a “slim,
loose-jointed boy, fond of the pretty intangibilities of romance, and of
dreaming when broad awake;”[35] and how, as a quarryman, he ever kept
his eyes open, to observe the results of every blow of the hammer,
stroke of the pick, or blast of the powder; and finding himself in the
midst of new and undreamt-of relics of an old creation, preserved in
“tables of stone,” he adds _his_ testimony to that of the great father
of inductive philosophy, “that it cannot be too extensively known, that
nature is vast and knowledge limited, and that no individual, however
humble in place or acquirement, need despair of adding to the general
fund.”[36]
We here enter upon a marvellous field of discovery. Hitherto the forms
of life we have met with have all been invertebrate. The trilobite,
something between a crab and a beetle, once revelling, in untold
myriads, probably on the land as well as in the water, and of which two
hundred and fifty species have been brought to light, is the highest
type of life with which our researches have made us familiar. We are now
to begin the study of fossil fish, and to their discovery, strange
forms, and characters, this chapter will be specially devoted. It was
once a generally received opinion among even the most learned
geologists, that the “old red sandstone,” or the “Devonian system,” was
particularly barren of fossils, but the labours (literally such, “mente,
manu, malleoque”[37]) of Hugh Miller have proved the contrary. “The
fossils,” he says, “are remarkably numerous, and in a state of high
preservation. I have a hundred solid proofs by which to establish the
proof of my assertion, within less than a yard of me. Half my closet
walls are covered with the peculiar fossils of the lower old red
sandstone; and certainty a stranger assemblage of forms have rarely been
grouped together; creatures whose very type is lost, fantastic and
uncouth, and which puzzle the naturalist to assign them even their
class; boat-like animals, furnished with oars and a rudder; fish plated
over like the tortoise, above and below, with a strong armour of bone,
and furnished with but one solitary rudder-like fin; other fish less
equivocal in their form, but with the membranes of their fins thickly
covered with scales; creatures bristling over with thorns, others
glistening in an enamelled coat, as if beautifully japanned, the tail in
every instance among the less equivocal shapes, formed not equally as in
existing fish, on each side the central vertebral column, but chiefly on
the lower side, the column sending out its diminished vertebræ to the
extreme termination of the fin. All the forms testify of a remote
antiquity—of a period whose fashions have passed away.”[38]
The old red sandstone formation prevails in the north of Scotland,
Herefordshire, north of Devonshire, part of Cornwall, and in
Worcestershire and Shropshire. Our attention will be principally
confined to Cromarty, whose romantic bay and high hills have long
arrested the admiring gaze of the traveller. This was the scene of Hugh
Miller’s labours and discoveries; this the great library in which he
read the history of pre-Adamite ichthyolites[39] exposed not only to the
light of day, but for the first time to the inspection of human eyes, by
the sweat-of-brow toil of one of Scotland’s noble sons. Before we get
into the hard names that must be connected with this chapter, let us
hear Mr. Miller describe this library of God’s books that was so long
his wonder and his study in Cromartyshire. “The quarry in which I
wrought lay on the southern shore of a noble inland bay, or frith
rather, with a little clear stream on the one side, and a thick fir-wood
on the other. Not the united labours of a thousand men for a thousand
years could have furnished a better section of the geology of this
district than this range of cliffs; it may be regarded as a sort of
chance dissection on the earth’s crust. We see in one place the primary
rock, with its veins of granite and quartz, its dizzy precipices of
gneiss, its huge masses of horneblend; we find the secondary rock in
another, with its beds of sandstone and shale, its spars, its clays, and
its nodular limestones. We discover the still little known, but very
interesting fossils of the old red sandstone in one deposition; we find
the beautifully preserved shell and lignites of the lias in another.
There are the remains of two several creations at once before us. The
shore, too, is heaped with rolled fragments of almost every variety of
rock,—basalts, ironstones, hyperstenes, porphyries, bituminous shales,
and micaceous schists. In short, the young geologist, had he all Europe
before him, could hardly choose for himself a better field. I had,
however, no one to tell me so at the time, for geology had not yet
travelled so far north; and so, without guide or vocabulary, I had to
grope my way as best I might, and find out all its wonders for myself.
But so slow was the process, and so much was I a seeker in the dark,
that the facts contained in these few sentiments were the patient
gatherings of years.”[40]
Now with regard to the hard names to which we have just made
allusion—names that, apart from their etymology, which is nothing more
than “sending vagrant words back to their parish,” are enough to startle
any one; names such as heterocercal, homocercal, cephalaspis,
pterichthys, coccosteus, osteolepis, &c. &c.—why, they will all
presently become plain, and, we hope, familiar to our readers. “They
are,” says Hugh Miller, “like all names in science, unfamiliar in their
aspect to mere English readers, just because they are names not for
England alone, but for England and the world. I am assured, however,
that they are all composed of very good Greek, and picturesquely
descriptive of some peculiarity in the fossils they designate.”[41]
The rest of this chapter will be occupied with an account of the four
most remarkable and characteristic fishes of this formation, to
understand which a few preliminary remarks are necessary. Cuvier divided
all fish into two groups, the _bony_ and the _cartilaginous_; and these
two groups he subdivided into two divisions, characterised by
differences in their _fins_, or organs of locomotion, one of which he
called Acanthopterygian,[42] (thorny-finned,) and the other,
Malacopterygian,[43] (or soft-finned.) This concise arrangement did not,
however, meet all the wants of the fish-students, and it was often
practically difficult to know under which class to arrange particular
specimens. More recently M. Agassiz has arranged fish, not according to
their _fins_, but according to their _scales_; and simple as this
classification may seem, it is one of the greatest triumphs of genius in
modern times, inasmuch as all fishes extinct and existing, that have
inhabited or are inhabiting the “waters under the earth,” may be grouped
easily under the following four divisions:—
[Illustration:
1. GANOID SCALE; as bony pike.[44]
]
[Illustration:
2. PLACOID SCALE.[45]
]
[Illustration:
3. CTENOID SCALE; as sole or perch.[46]
]
[Illustration:
4. CYCLOID SCALE; as herring.[47]
]
One more preliminary remark, and we will proceed to look at the four
fishes already alluded to. Neither the teacher nor the student of any
science can skip definitions, axioms, postulates, and so on; they must
just be mastered, and their mastery is a real pleasure. In addition to a
marked difference in the _fins_, a difference was observed also in the
_tails_ of fossil (extinct) and living pieces of fish. This difference
between the tails of fish has been happily described in two words,
heterocercal and homocercal, of which the figures below will give a
better idea than a lengthened description.
[Illustration:
1. HETEROCERCAL.
]
[Illustration:
2. HOMOCERCAL.
]
[Illustration:
3. HOMOCERCAL.
]
The _heterocercal_ fish, it will be seen, are unequally lobed, that is,
the spinal vertebræ are prolonged into the upper lobe of the tail, as
seen in the shark, and of which our own dog-fish is an example; while
the homocercal fish are equally lobed, and the spine does not extend
into either.
The fossil fish of the old red sandstone belong almost, if not entirely,
to the classes of fish that have ganoid or placoid scales, and
heterocercal tails; and of these fish we will now say a few words of the
four most remarkable specimens of the one thousand and upwards fossil
species that have been discovered, and which can only be known
familiarly by accomplished geologists in the ichthyolite department.
[Illustration: Fossil]
1. Here is a drawing of the Cephalaspis,[48] or buckler-headed fish.
What an extraordinary looking creature this is! Like the crescent shape
of a saddler’s knife without the handle—broad and flat, with points on
each side running down, ever fixed in warlike attitude against its
enemies—it reminds one of an extinct trilobite, and of a living sole or
ray, at the same time; and one can easily fancy how hard it must have
been for its ancient foes to swallow down so singular and so knife-like
looking a creature. This is one of the curious organisms of old life
discovered in Cromarty, Herefordshire, and in Russia, the original of
which, restored in the drawing, seldom if ever exceeded seven inches.
Let us look now at another curiosity from the same quarter.
[Illustration: Fossil]
2. Here is a drawing of the Coccosteus,[49] or berry-boned fish. This
creature is equally singular with his long extinct neighbour. Hugh
Miller’s description is the best, and as he was its discoverer, let us
give it.
“The figure of the Coccosteus I would compare to a boy’s kite; there is
a rounded head, a triangular body, a long tail attached to the apex of
the triangle, and arms thin and rounded where they attach to the body,
and spreading out towards their termination, like the ancient one-sided
shovel which we see sculptured on old tombstones, or the rudder of an
ancient galley. A ring of plates, like the ring-stones of an arch, runs
along what we may call the hoop of the kite. The form of the key-stone
plate is perfect; the shapes of the others are elegantly varied, as if
for ornament; and what would be otherwise the opening of the arch is
filled up with one large plate of an outline singularly elegant.”[50]
[Illustration: Fossil]
3. Above is the Pterichthys,[51] or winged fish. We have here a fish
more strikingly different to any existing species than either of the
other two just passed under review. “Imagine,” says Miller, “the figure
of a man rudely drawn in black on a grey ground; the head cut off by the
shoulders; the arms spread at full, as in the attitude of swimming; the
body rather long than otherwise, and narrowing from the chest downwards;
one of the legs cut away at the hip-joint; the other, as if to preserve
the balance, placed directly in the centre of the figure, which it seems
to support. Such, at the first glance, is the appearance of the
fossil.”[52]
We will now turn to the fourth and last of the singular fishes of this
formation.
[Illustration: Fossil]
4. The Osteolepis,[53] or bony scaled fish. Here we have in the old red
sandstone the first perfect specimen of a fish with pectoral, abdominal,
and caudal fins, ending as the others do in the heterocercal tail. The
vertebral column seems to have run on to well-nigh the extremity of the
caudal fin, which we find developed chiefly on the under side. The tail
was a one-sided tail. Take into account with these peculiarities such as
the naked skull, jaws, and operculum,[54] the naked and thickly set
rays, and the unequally lobed condition of tail, a body covered with
scales that glitter like sheets of mica, and assume, according to their
position, the parallelogramical, rhomboidal, angular, or polygonal form,
a lateral line raised, not depressed, a raised bar on the inner or bony
side of the scales, which, like the doubled up end of a tile, seems to
have served the purpose of fastening them in their places, a general
clustering of alternate fins towards the tail—and the _tout ensemble_
must surely impart to the reader the idea of a very singular little
fish.[55]
Most hasty and superficial is this glance through the wonders of the old
red sandstone. On the economic uses of this formation, as _tile-stones_
and _paving-stones_, we need not dwell; apart from this, these singular
inhabitants of the seas of past ages, the mud of which, elevated and
hardened, has become solid rock, tell us stories of that long since
ancient time to which no poetry could do justice. Carried away from the
present into those remote eras, our minds revel in the realization of
scenery and inhabitants, of which now we possess only the fossil
pictures. At the British Museum, we gaze with feelings approaching to
repulsion on the stiff and unnatural forms of Egyptian mummies, but with
what feelings of profound wonder do we look on these small fishes, so
numerous that the relics of them, found in the Orkneys, may be carried
away by cartloads! No number of creations can exhaust God, for in Him
all fulness dwelleth. The God in whom we now live, and move, and have
our being, is the same God who gave to these pre-Adamite fish their
marvellous structures, minutely but fearfully and wonderfully made, and
who, when their joy of life and functions of life had ceased, consigned
them to a calm and peaceful grave. He is the same God who now upholds
all things by the word of his power, and whom we desire to honour by the
attentive and reverent perusal of his manifold works. _We_ are
tautologists; we say and do the same thing over and over again. God
never repeats himself: each successive creation—and how many, extending
through countless ages, does geology disclose!—only reveals some new
aspect of wisdom, love, and beneficence. To the mind that cannot repose
in God, we say, Study God, in his works and in his word; yea, come back
to this remote sandstone era and ask of the “fishes, and they shall
declare unto thee” the might and majesty, the skill and contrivance of
the Almighty; and though you and I were not there, nor had Adam yet trod
this blessed earth,—
“Think not, though men were none,
That heaven could want spectators, God want praise;
Millions of spiritual creatures walked the earth,
And these with ceaseless praise His works beheld.”