Chapter 47

chapter, that the Hill had its dense thickets, which, from the gloom that brooded in their recesses even at mid-day, were known to the boys of the neighbouring town as the "dungeons." They had now fared, however, in this terrible overturn, like dungeons elsewhere in times of revolution, and were all swept away; and piles of prostrate trees--in some instances ten or twelve in a single heap marked where they had stood. In several localities, where they fell over swampy hollows, or where deep-seated springs came gushing to the light, I found the water partially dammed up, and saw that, were they to be left to cumber the ground as the debris of forests destroyed by hurricanes in the earlier ages of Scottish history would certainly have been left, the deep shade and the moisture could not have failed to induce a total change in the vegetation. I marked, too, the fallen trees all lying one way, in the direction of the wind; and the thought at once struck me, that in this recent scene of devastation I had the origin of full one-half of our Scottish mosses exemplified. Some of the mosses of the south date from the times of Roman invasion. Their lower tiers of trunks bear the mark of the Roman axe; and in some instances, the sorely wasted axe itself--a narrow, oblong tool, somewhat resembling that of the American backwoodsman--has been found sticking in the buried stump Some of our other mosses are of still more modern origin: there exist Scottish mosses that seem to have been formed when Robert the Bruce felled the woods and wasted the country of John of Lorn. But of the others, not a few have palpably owed their origin to violent hurricanes, such as the one which on this occasion ravaged the Hill of Cromarty. The trees which form their lower stratum are broken across, or torn up by the roots, _and their trunks all lie one way_. Much of the interest of a science such as geology must consist in the ability of making dead deposits represent living scenes; and from this hurricane I was enabled to conceive, pictorially, if I may so express myself, of the origin of those comparatively recent deposits of Scotland which, formed almost exclusively of vegetable matter, contain, with rude works of art, and occasionally remains of the early human inhabitants of the country, skeletons of the wolf, the bear, and the beaver, with horns of the _bos primigenius_ and _bos longifrons_, and of a gigantic variety of red deer, unequalled in size by animals of the same species in these latter ages. Occasionally I was enabled to vivify in this way even the ancient deposits of the Lias, with their vast abundance of cephalopodous mollusca--belemnites, ammonites, and nautili. My friend of the Cave had become parish schoolmaster of Nigg; and his hospitable dwelling furnished me with an excellent centre for exploring the geology of the parish, especially its Liassic deposits at Shandwick, with their huge gryphites and their numerous belemnites, of at least two species, comparatively rare at Eathie--the _belemnite abreviatus_ and _belemnite elongatus_. I had learned that these curious shells once formed part of the internal framework of a mollusc more nearly akin to the cuttle-fishes of the present day than aught else that now exists; and the cuttle-fishes--not rare in at least one of their species (_loligo vulgare_) in the Firth of Cromarty--I embraced every opportunity of examining. I have seen from eighteen to twenty individuals of this species enclosed at once in the inner chamber of one of our salmon-wears. The greater number of these shoals I have ordinarily found dead, and tinged with various shades of green, blue, and yellow--for it is one of the characteristics of the creature to assume, when passing into a state of decomposition, a succession of brilliant colours; but I have seen from six to eight individuals of their number still alive in a little pool beside the nets, and still retaining their original pink tint, freckled with red. And these I have observed, as my shadow fell across their little patch of water, darting from side to side in panic terror within the narrow confines, emitting ink at almost every dart, until the whole pool had become a deep solution of sepia. Some of my most interesting recollections of the cuttle-fish are associated, however, with the capture and dissection of a single specimen. The creature, in swimming, darts through the water much in the manner that a boy slides down an ice-crusted declivity, feet foremost;--the lower or nether extremities go first, and the head behind: it follows its tail, instead of being followed by it; and this curious peculiarity in its mode of progression, though, of course, on the whole, the mode best adapted to its conformation and instincts, sometimes proves fatal to it in calm weather, when not a ripple breaks upon the pebbles, to warn that the shore is near. An enemy appears: the creature ejects its cloud of ink, like a sharp-shooter discharging his rifle ere he retreats; and then, darting away, tail foremost, under cover of the cloud, it grounds itself high upon the beach, and perishes there. I was walking, one very calm day, along the Cromarty shore, a little to the west of the town, when I heard a peculiar sound--a _squelch_, if I may employ such a word--and saw that a large loligo, fully a foot and a half in length, had thrown itself high and dry upon the beach. I laid hold of it by its sheath or sack; and the loligo, in turn, laid hold of the pebbles, apparently to render its abduction as difficult as possible, just as I have seen a boy, when borne off against his will by a stronger than himself, grasping fast to door-posts and furniture. The pebbles were hard and smooth, but the creature raised them very readily with his suckers. I subjected one of my hands to its grasp, and it seized fast hold; but though the suckers were still employed, it made use of them on a different principle. Around the circular rim of each there is a fringe of minute thorns, hooked somewhat like those of the wild rose. In clinging to the hard polished pebbles, these were overlapped by a fleshy membrane, much in the manner that the cushions of a cat's paw overlap its claws when the animal is in a state of tranquillity; and by means of the projecting membrane, the hollow interior was rendered air-tight, and the vacuum completed: but in dealing with the hand--a soft substance--the thorns were laid bare, like the claws of a cat when stretched out in anger, and at least a thousand minute prickles were fixed in the skin at once. They failed to penetrate it, for they were short, and individually not strong; but, acting together by hundreds, they took at least a very firm hold.

What follows may be deemed barbarous; but the men who gulp down at a sitting half-a-hundred live oysters to gratify their taste, may surely forgive me the destruction of a single mollusc to gratify my curiosity! I cut open the sack of the creature with a sharp penknife, and laid bare the viscera. What a sight for Harvey, when prosecuting, in the earlier stages, his grand discovery of the circulation! _There_, in the centre, was the yellow muscular heart, propelling into the transparent, tubular arteries, the _yellow_ blood. Beat--beat--beat:--I could see the whole as in a glass model; and all I lacked were powers of vision nice enough to enable me to detect the fluid passing through the minuter arterial branches, and then returning by the veins to the _two_ other hearts of the creature; for, strange to say, it is furnished with three. There in the midst I saw the yellow heart, and, lying altogether detached from it, two other deep-coloured hearts at the sides. I cut a little deeper. _There_ was the gizzard-like stomach, filled with fragments of minute mussel and crab shells; and _there_, inserted in the spongy, conical, yellowish-coloured liver, and somewhat resembling in form a Florence flask, was the ink-bag distended, with its deep dark sepia--the identical pigment sold under that name in our colour shops, and so extensively used in landscape drawing by the limner. I then dissected and laid open the circular or ring-like brain that surrounds the creature's parrot-like beak, as if its _thinking_ part had no other vocation than simply to take care of the mouth and its pertinents--almost the sole employment, however, of not a few brains of a considerably higher order. I next laid open the huge eyes. They were curious organs, more simple in their structure than those of the true fishes, but admirably adapted, I doubt not, for the purposes of seeing. A camera obscura may be described as consisting of two parts--a lens in front, and a darkened chamber behind; but in the eyes of fishes, as in the brute and human eye, we find a third part added: there is a lens in the middle, a darkened chamber behind, and a lighted chamber, or rather vestibule, in front. Now, this lighted vestibule--the cornea--is wanting in the eye of the cuttle-fish. The lens is placed in front, and the darkened chamber behind. The construction of the organ is that of a common camera obscura. I found something worthy of remark, too, on the peculiar style in which the chamber is darkened. In the higher animals it may be described as a chamber hung with black velvet--the _pigmentum nigrum_ which covers it is of the deepest black; but in the cuttle-fish it is a chamber hung with velvet, not of a black, but of a dark purple hue--the _pigmentum nigrum_ is of a purplish red colour. There is something interesting in marking this first departure from an invariable condition of eyes of the more perfect structure, and in then tracing the peculiarity downwards through almost every shade of colour, to the emerald-like eye-specks of the pecten, and the still more rudimentary red eye-specks of the star-fish. After examining the eyes, I next laid open, in all its length, from the neck to the point of the sack, the dorsal bone of the creature--its internal shell, I should rather say, for bone it has none. The form of the shell in this species is that of a feather, equally developed in the web on both sides. It gives rigidity to the body, and furnishes the muscles with a fulcrum; and we find it composed, like all other _shells_, of a mixture of animal matter and carbonate of lime. Such was the lesson taught me in a single walk; and I have recorded it at some length. The subject of it, the loligo, has been described by some of our more distinguished naturalists, such as Kirby in his Bridgewater Treatise, as "one of the most wonderful works of the Creator;" and the reader will perhaps remember how fraught with importance to natural science an incident similar to the one related proved in the life of the youthful Cuvier. It was when passing his twenty-second year on the sea-coast, near Fiquainville, that this greatest of modern naturalists was led, by finding a cuttle-fish stranded on the beach, which he afterwards dissected, to study the anatomy and character of the mollusca. To me, however, the lesson served merely to vivify the dead deposits of the Oolitic system, as represented by the Lias of Cromarty and Ross. The middle and later ages of the great secondary division were peculiarly ages of the cephalopodous molluscs: their belemnites, ammonites, nautili, baculites, hamites, turrilites, and scaphites, belonged to the great natural class--singularly rich in its extinct orders and genera, though comparatively poor in its existing ones--which we find represented by the cuttle-fish; and when engaged in disinterring the remains of the earlier-born members of the family--ammonites, belemnites, and nautili--from amid the shales of Eathie or the mud-stones of Shandwick, the incident of the loligo has enabled me to conceive of them, not as mere dead remains, but as the living inhabitants of primæval seas, stirred by the diurnal tides, and lighted up by the sun.

When pursuing my researches amid the deposits of the Lias, I was conducted to an interesting discovery. There are two great systems of hills in the north of Scotland--an older and a newer--that bisect each other like the furrows of a field that had first been ploughed across and then diagonally. The diagonal furrows, as the last drawn, are still very entire. The great Caledonian Valley, open from sea to sea, is the most remarkable of these; but the parallel valleys of the Nairn, of the Findhorn, and of the Spey, are all well-defined furrows; nor are the mountain ridges which separate them less definitely ranged in continuous lines. The ridges and furrows of the earlier ploughing are, on the contrary, as might be anticipated, broken and interrupted: the effacing plough has passed over them: and yet there are certain localities in which we find the fragments of this earlier system sufficiently entire to form one of the main features of the landscape. In passing through the upper reaches of the Moray Firth, and along the Caledonian Valley, the cross furrows may be seen branching off to the west, and existing as the valleys of Loch Fleet, of the Dornoch Firth, of the Firth of Cromarty, of the Bay of Munlochy, of the Firth of Beauty, and, as we enter the Highlands proper, as Glen Urquhart, Glen Morrison, Glen Garry, Loch Arkaig, and Loch Eil. The diagonal system--represented by the great valley itself, and known as the system of Ben Nevis and the Ord of Caithness in our own country, and, according to De Beaumont, as that of Mount Pilate and Coté d'Or on the Continent--was upheaved after the close of the Oolitic ages. It was not until at least the period of the Weald that its "hills had been formed and its mountains brought forth;" and in the line of the Moray Firth the Lias and Oolite lie uptilted, at steep angles, against the sides of its long ranges of precipice. It is not so easy determining the age of the older system. No formation occurs in the north of Scotland between the Lias and the Old Red Sandstone: the vast Carboniferous, Permian, and Triassic deposits are represented by a wide gap; and all that can be said regarding the older hills is, that they disturbed and bore up with them the Old Red Sandstone; but that as there lay at their bases, at the time of their upheaval, no more modern rock to be disturbed, it seems impossible definitely to fix their era. Neither does there appear among their estuaries or valleys any trace of the Oolitic deposits. Existing, in all probability, during even the times of the Lias, as the sub-aërial framework of Oolitic Scotland--as the framework on which the Oolitic vegetables grew--no deposit of the system could of course have taken place over them. I had not yet, however, formed any very definite idea regarding the two systems, or ascertained that they belonged apparently to a different time; and finding the Lias upheaved against the steeper sides of the Moray Firth--one of the huge furrows of the more modern system--I repeatedly sought to find it uptilted also against the shores of the Cromarty Firth--one of the furrows of the greatly more ancient one. I had, however, prosecuted the search in a somewhat desultory manner; and as in the autumn of 1830 a pause of a few days took place in my professional labours between the completing of one piece of work and the commencement of another, I resolved on devoting the time to a thorough survey of the Cromarty Firth, in the hope of detecting the Lias. I began my search at the granitic gneiss of the Hill, and, proceeding westwards, passed in succession, in the ascending order, over the uptilted beds of the lower Old Red Sandstone, from the Great Conglomerate base of the system, till I reached the middle member of the deposit, which consists, in this locality, of alternate beds of limestone, sandstone, and stratified clay, and which we find represented in Caithness by the extensively developed flag-stones. And then, the rock disappearing, I passed over a pebbly beach mottled with boulders; and in a little bay not half a mile distant from the town, I again found the rock laid bare.

I had long before observed that the rock rose to the surface in this little bay; I had even employed, when a boy, pieces of its stratified clay as slate-pencil; but I had yet failed minutely to examine it. I was now, however, struck by its resemblance, in all save colour, to the Lias. The strata lay at a low angle: they were composed of an argillaceous shale, and abounded in limestone nodules; and, save that both shale and nodules bore, instead of the deep Liassic grey, an olivaceous tint, I might have almost supposed I had fallen on a continuation of some of the Eathie beds. I laid open a nodule with a blow of the hammer, and my heart leaped up when I saw that it enclosed an organism. A dark, ill-defined, bituminous mass occupied the centre; but I could distinguish what seemed to be spines and small ichthyic bones projecting from its edges; and when I subjected them to the scrutiny of the glass, unlike those mere chance resemblances which sometimes deceive for a moment the eye, the more distinct and unequivocal did their forms become. I laid open a second nodule. It contained a group of glittering rhomboidal scales, with a few cerebral plates, and a jaw bristling with teeth. A third nodule also supplied its organism, in a well-defined ichthyolite, covered with minute, finely-striated scales, and furnished with a sharp spine in the anterior edge of every fin. I eagerly wrought on, and disinterred, in the course of a single tide, specimens enough to cover a museum table; and it was with intense delight that, as the ripple of the advancing tide was rising against the pebbles, and covering up the ichthyolitic beds, I carried them to the higher slopes of the beach, and, seated on a boulder, began carefully to examine them in detail with a common botanist's microscope. But not a plate, spine, or scale, could I detect among their organisms, identical with the ichthyic remains of the Lias. I had got amid the remains of an entirely different and incalculably more ancient creation. My new-found organisms represented, not the first, but merely the second age of vertebrate existence on our planet; but as the remains of the earlier age exist as the mere detached teeth and spines of placoids, which, though they give full evidence of the _existence_ of the fishes to which they belong, throw scarce any light on their structure, it is from the ganoids of this second age that the palæontologist can with certainty know under what peculiarities of form, and associated with what varieties of mechanism, vertebral life existed in the earlier ages of the world. In my new-found deposit--to which I soon added, however, within the limits of the parish, some six or eight deposits more, all charged with the same ichthyic remains--I found I had work enough before me for the patient study of years.