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utility and vital interest of the Triassic formation to man. When the rains and weather have decomposed this rock it remains only as a sterile and permeable sand. Striking as it is in its tall gaunt spectral peaks and pinnacles, wherever it exclusively prevails, as in the Vorarlberg and the lateral valleys of the Engadine, the vegetation is impoverished, the trees and bushes are scrubby, and the meadows and pastures are clothed with but a thin herbage, while the highest regions are completely arid. In one dolomite region, the valley of Mora, vegetation is utterly wanting, and from the base to the shattered summits of its mountains nothing is presented to the eye but a scene of desolation suggestive of the valley of the shadow of death. This is the more noteworthy as it forms a decided contrast to the usefulness of the other Triassic deposits to man. They afford to him copper and salt and gypsum ; and when the containing rocks are decomposed, good manure. They likewise yield to man therapeutic mineral waters impregnated with sulphur, as at Schinznach, and iodine, as at Wildegg, both of which probably have their sources in the gypsum. Thousands there are annually benefited by the product of the old Trias, while the eye is refreshed by the rich grasses, the fertile fields, and the productive vines which flourish on this formation, the rocks of which also afford excellent building stone for houses in villages and towns, for churches and cathedrals. We conjecture that the grand cathedral at Strasburg is built of the Trias of Alsace. Plainly it is constructed of a red sandstone like that of the Trias, and as this abounds in the vicinity, it seems warrantable to conclude that from thence the cathedral-building stone was drawn.
Ascending to and arriving at the Lias, we reach a formation specially developed and highly fossiliferous in England, but very far less so in Switzerland. The climatic conditions were manifestly identical in both countries, and so are the petrological, for the rocks of Charmouth and Lyme Regis in Dorsetshire closely resemble those of Schambelen on the banks of the river Reuss in Switzerland. This place is situated in the ancient Vindonissa, but we are now concerned in a far more ancient phase of its history than anything that concerns the old German emperors. It is a poor spot scenically and commercially, yet while it has no interests for tourists, it has a special attraction for Swiss paleontologists. Dr. Heer has resorted to it with unabated ardour and curiosity, and has made much of its fossiliferous fragments, regarding them as precious beyond many others, and as illustrating one of the most interesting episodes of Swiss terrestrial paleontology. To
the ordinary wayfarer it is a mass of rubbish, to Dr. Heer it is a mine of historical wealth.
It is evident that the different beds were deposited at Schambelen in a tranquil time, and so sheltered from stormy interruptions as to allow of the preservation of the remains of frail and minute creatures, which have come down to us as though they had been kept in a stony vase through innumerable centuries of disturbance and varied conditions. Each of the twenty-one beds is, as it were, a memorial volume of its period, and by its petrological constitution or fossiliferous contents indicates what climate and order of nature then prevailed. Two beds destitute of fossils bound and limit intermediate layers, of which about one-half are fossiliferous. The second and the last but one in the latter series produce ophiuridæ, or species of small star-fish, and the last six contain marine remains exclusively. Fragments of insects appear in the seventh layer in small numbers, more rarely in the ninth, but in great quantity in the eleventh. The eighteenth contains insects, and, like the seventh, in conjunction with them traces of marine animals. It is manifest that only the most tranquil kind of sedimentary deposition could have conserved remains of such fragile frames, and probably they lived between rock walls, which destroyed the force of the sea waves, and they must have been suddenly and safely packed up in the strong vase, or otherwise it is impossible to account for their exact and perfect conservation to our time.
This stone museum of Schambelen is rich indeed in its contents, for on the whole it holds 22 species of plants, and 182 species of animals, of which 11 represent fishes, 1 a reptile, and 143 various insects; 6 are crustaceans, 17 molluscs, and 4 radiated animals. When we proceed to study each class we can depict an imaginary restoration of the successive periods and their respective accompanying living things-marine plants, terrestrial plants, and especially insects, all following each other in due order. Of the insects 2,000 specimens derived from Schambelen represent 143 species, all belonging to the most ancient insects of the country, and therefore possessing a particular interest. Insects began to live in the Carboniferous period, judging from a fragment of a wing of one of the Blattidæ (black beetles or cockroaches), which is, according to our present knowledge, the most ancient fossil of the animal race in all Switzerland. But the primeval beetle had nearly sole supremacy in its extreme antiquity, since from the Carboniferous to the Triassic period there have been found only two species of insects; and only three others until we arrive at the Lias.
That so delicate a structure as the wing of an insect should be petrified, and, as in some examples, that every nervure or fibre of its framework should be marked out in stone, is indeed surprising. Mostly, however, the nervures are obliterated, and we have only the outline of the wing or the whole insect. The lithographic slate at Solenhofen in Germany affords numerous insect remains, some being clearly defined and precisely preserved. Our English Lias has also afforded us fiftysix species of insects, seldom indeed very clearly distinguished. There are in particular parts of our liassic and colitic formations very thin layers of stone which are known as the 'Insect beds,' and by a careful separation of the finely laminated parts of these beds we sometimes disinter the fragments of many ancient insects; and therefrom we are able to reconstruct an imaginary natural life-scene in primeval England similar to one of the same age as Schambelen in Switzerland. From various entomological fossils found in the South of England, principally in Gloucestershire, Somersetshire, Dorsetshire, and Warwickshire, often mingled with remnants of tropical plants, we infer that insects of the Cicada family once crept amongst the thick herbs, that dragon-flies balanced themselves in the air, while busy beetles and ants sought their nutriment in the forests, and wood-vermin chased others for their prey, while on the surface of adjacent streams active water-beetles exercised their limbs in their peculiar mode of aqueous progression. Returning from such an English scene to Switzerland, we observe that the organic life of Schambelen was not merely a local phenomenon, but one associated with our own life of the same period. The rocks are much the same, and so were the entomological fauna in character, though not in species. The same, too, may even be stated with reference to the Lias of the Black Forest, and some parts of the South of Germany. Schambelen, then, is a typical spot; and is so specially enriched with fossils that we may take our stand upon it and from it judge of the coeval remains in other countries.
Let us place ourselves on an eminence which commands the bay or basin of this place in the primeval Liassic period of life. We repose under the shadow of a huge cycad ; the morning air passes fresh and pure across the sharp leaves. The neighbouring heights are crowned with cycads of hard and pinnated foliage. A river rolls at our feet, whose banks are covered hover great dragon-flies, having large and reticulated wings, and these enter occasionally amongst the reeds of the banks, whilst brilliant beetles (Buprestidæ) and agile Elateridæ sport around them. There is more sunlight now than during the Carboniferous era. The vast clouds of carbonic acid gas which then prevailed have been assimilated by the vegetation of that period, which has been long ago buried in the earth as a provision for the coal and the carbonaceous fuel of far future ages. The air has become lighter, and everywhere the sun exercises a more vivifying influence. These brilliant and hovering, and flying insects are a lively proof of it. There are more of them than we can see at a glance or in a day. The sluggish waters have already become loaded with their dead, and dried leaves of plants are gradually accumulating with these to contribute to the sandy layers of our day.
A foot or two of rocky thickness is now the sepulchre of all this bright and busy insect and plant life. To this succeeds a calcareous deposit of some ten feet in which we do not discover any traces of the organisms of firm land ; in place of which we meet with cylindrical branching bodies, in all probability derived from marine plants. Then come chambered shells; Ammonites, Rhynconella, Pleurotomaria, and slender Belemnites, and afterwards the very common and characteristic Gryphite. Of the species and structure of each of these shells much may be said, but our own narrow limits hurry us through the ages, and we pass on.
The term “ Jurassic' is not the same geologically and geographically. In the latter sense it is derived from the vast range of the Jura Mountains in the west of Switzerland, while geologically it is employed to denote an epoch. Dr. Heer treats of the Jurassic Sea by itself, after having regarded the liassic as a definite preceding epoch, and noticed as such its various minor deposits in Switzerland. As so many of our tourists annually see the Jura Mountains either immediately before them or from a distance, it will specially interest them if we depict the primitire condition of that range when it was for the most part under water and in process of formation. When from Neuchâtel we ascend to the Chaumont in clear and bright weather, we beheld a rast panorama of Alpine summits extending from the Sentis to Mont Blanc, and the idea of infinitr is strongly impressed on our minds. The same impression is made upun us when we see the vast espanse of the lerel ocean. From our assumed standing place of todar, pre mar in imagination dubine the elements of both pictures, the sta irteer being ner wir absent, but its
numerocean rolled, and beyond the "Juwith multitudes of Jura
effects and remnants compose the very mountains on which we stand. No long marine voyages of discovery are necessary for us, since we now are in the middle of a large ancient marine bay, the waters of which have been long ago dried up and the bottom solidified. Restoring by a mental effort the primeval conditions of the Jura range, we perceive at one time vast banks of coral forming entire sides of rock, and myriads of animals busily constructing these calcareous masses. Despite the minuteness and frailty of these little architects, they erect buildings which endure through all subsequent ages, and they are in fact the mountain-makers of this lofty range; insignificant utterly as compared with man, they have laboured more incessantly, and they have constructed more extensively. In these remains of marine animals, of urchins and starfishes and molluscs, we have the relics of a sea-coast richer in such creatures than any coast now known. The whole Jura Mountains of our day were then alive with multitudes of these creatures. Far, too, beyond the Juras the waters of the same ocean rolled, and far beyond their present bounds innumerable troops of like marine animals were engaged in building up similar rocks, similar corals, until finally they perished and were entombed in a like sepulchre.
We can in some degree trace out the extent of the surface of this sea; can we fairly conjecture its depths ? Now the Juras offer piles of rocks filled with the débris of animals, and other piles of as great extent which are completely bare of them. The former were probably formed near to coasts and in comparatively shallow waters, while, on the contrary, the latter, particularly where they are fine-grained rocks, were composed of masses of slime or clay deposited at great depths where all life ceased. It is not correct to say that life exists at all depths of the ocean, as some particularly favourable soundings are supposed to establish; for in the deep seas as on the broad lands there are localities which afford homes to many animals, and others which are entirely lifeless and desolate.
A comparison of all now known of submarine life at large with the fossils of the Jura will enable us to arrive at some conception of the depths, the succession, and the characteristics of marine life in the Jurassic Sea. Immediately after the lias there appears a marl of a sombre colour, then numerous bands of partly calcareous and partly sandy and marly rocks. The lower layers of these are particularly brown, while the upper ones are of a white and a yellowish-white hue. The upper ones are termed the White Jura, and the lower ones the Brown