We now arrive at the proofs of design manifested in the fossil remains of mollusks,-those soft-bodied animals, some of which are naked while others are protected by a shell. The great majority of these testaceans have their living representatives, and the evidence, therefore, to be derived from the ancient species is much the same with that to be collected from the modern. There are, however, some instances, even where the type is still continued, well worthy of notice; while in others, where the family is utterly extinct, the proofs of consummate skill in the fabrication of their shells, when considered in relation to the exigencies of the animals, are most abundant.

Every one has heard or read of the viscid ink-like substance, the nigra succus loliginis' with which the cuttle clouds the water for the purpose of concealment. It was, indeed, hardly to be expected that traces of so subtle a fluid should be found among the remains of extinct cephalopods, that had perished suddenly countless centuries ago. Yet, Miss Mary Anning, to whom geologists are so much indebted for having brought to light the saurian and other remains of Lyme, found this substance at that locality, and, in February, 1829, Dr. Buckland announced to the Geological Society of London, the fossil pens' and 'fossil inkbags' of the lias.

So completely,' says the Doctor, are the character and qualities of the ink retained in its fossil state, that when, in 1826, I submitted a portion of it to my friend Sir Francis Chantrey, requesting him to try its power as a pigment, and he had prepared a drawing with a triturated portion of this fossil substance; the drawing was shown to a celebrated painter, without any information as to its origin, and he immediately pronounced it to be tinted with sepia of excellent quality, and begged to be informed by what colourman it was prepared. The common sepia used in drawing is from the ink-bag of an oriental species of cuttle-fish. The ink of the cuttle-fishes, in its natural state, is said to be soluble only in water, through which it diffuses itself instantaneously; being thus remarkably adapted to its peculiar service in the only fluid wherein it is naturally employed.'-p. 305.

There can be no doubt that the 'fossil pens' were the internal horny bodies which, like the transparent 'pen' of the recent species, afforded support to the softer parts of the ancient animal, thus showing that the same principles of construction now in operation, prevailed at periods incalculably remote.

'The petrified remains of fossil loligo, therefore, add another link to the chain of argument which we are pursuing, and aid us in connecting successive systems of creation which have followed each other upon our planet, as parts of one grand and uniform design. . Paley has beautifully, and with his usual felicity, described the unity and universality of providential care, as extending from the construc

tion of a ring of two hundred thousand miles diameter, to surround the body of Saturn, and be suspended, like a magnificent arch, above the heads of his inhabitants, to the concerting and providing an appropriate mechanism for the clasping and reclasping of the filaments in the feather of the humming-bird. The geologist descries a no less striking assemblage of curious provisions and delicate mechanisms, extending from the entire circumference of the crust of our planet, to the minutest curl of the smallest fibre in each component lamina of the pen of the fossil loligo. He finds these pens uniformly associated with the same peculiar defensive provision of an internal ink-bag, which is similarly associated with the pen of the living loligo in our actual seas; and hence he concludes, that such a union of contrivances, so nicely adjusted to the wants and weaknesses of the creatures in which they occur, could never have resulted from the blindness of chance, but could only have originated in the will and intention of one and the same Creator.'-pp. 306-310.

Come we now to the proofs of design in the mechanism of fossil chambered shells-the nautilite and ammonite, for instance. Here it is to be remembered that the object was not merely to produce defences for the bodies of the animals, but to form, at the same time, hydraulic instruments of delicate adjustment constructed to act in subordination to those universal and unchanging laws which appear to have ever regulated the movement of fluids. We select the ammonite; and we shall find that a more perfect machine than its shell for affording resistance to external pressure, combining the utmost degree of lightness and buoyancy with the greatest strength, could hardly be imagined:

• What nice hand,

With twenty years' apprenticeship to boot,
Will make us such another?'

'In more than two hundred known species of ammonites, the transverse plates present some beautifully varied modifications of this foliated expansion at their edges; the effect of which, in every case, is to increase the strength of the outer shell, by multiplying the subjacent points of resistance to external pressure. We know that the pressure of the sea at no great depth will force a cork into a bottle filled with air, or crush a hollow cylinder or sphere of thin copper; and as the air chambers of ammonites were subject to similar pressure, whilst at the bottom of the sea, they required some peculiar provision to preserve them from destruction,* more especially as most zoologists agree that they existed at great depths.

• Here

*Captain Smyth found, on two trials, that the cylindrical copper air-tube, under the vane attached to Massey's patent log, collapsed, and was crushed quite flat under a pressure of about three hundred fathoms. A claret bottle, filled with air, and well corked, was burst before it had descended four hundred fathoms. He also found that a bottle filled with fresh water, and corked, had the cork forced at about a hundred and eighty fathoms below the surface; in such cases, the fluid sent down is

replaced

Here again we find the inventions of art anticipated in the works of nature, and the same principle applied to resist the inward pressure of the sea upon the shells of ammonites, that an engineer makes use of in fixing transverse stays beneath the planks of the wooden centre on which he builds his arch of stone.

The disposition of these supports assumes throughout the family of ammonites a different arrangement from the more simple curvature of the edges of the transverse plates within the shells of nautili; and we find a probable cause for this variation, in the comparative thinness of the outer shells of many ammonites; since this external weakness creates a need of more internal support under the pressure of deep water, than was requisite in the stronger and thicker shells of nautili.

This support is effected by causing the edges of the transverse plates to deviate from a simple curve into a variety of attenuated ramifications and undulating sutures. Nothing can be more beautiful than the sinuous windings of these sutures in many species, at their union with the exterior shell; adorning it with a succession of most graceful forms, resembling festoons of foliage, and elegant embroidery. When these thin septa are converted into iron pyrites, their edges appear like golden filigrane work, meandering amid the pellucid spar that fills the chambers of the shell. . On examining the

proofs of contrivance and design that pervade the testaceous remains of the family of ammonites, we find, in every species, abundant evidence of minute and peculiar mechanisms, adapting the shell to the double purpose of acting as a float, and of forming a protection to the body of its inhabitant.

As the animal increased in bulk, and advanced along the outer chamber of the shell, the spaces left behind it were successively converted into air-chambers, simultaneously increasing the power of the float. This float, being regulated by a pipe, passing through the whole series of the chambers, formed an hydraulic instrument of extraordinary delicacy, by which the animal could, at pleasure, control its ascent to the surface, or descent to the bottom of the sea.

To creatures that sometimes floated, a thick and heavy shell would have been inapplicable; and as a thin shell, inclosing air, would be exposed to various and often intense degrees of pressure at the bottom, we find a series of provisions to afford resistance to such pressure, in the mechanical construction both of the external shell, and of the internal transverse plates which formed the air-chambers.

replaced by salt water, and the cork which had been forced in, is sometimes inverted.

6

Captain Beaufort also informs me, that he has frequently sunk corked bottles in the sea more than a hundred fathoms deep, some of them empty, and others con-taining a fluid. The empty bottles were sometimes crushed, at other times the cork was forced in, and the bottle returned full of sea-water. The cork of the bottles containing a fluid was uniformly forced in, and the fluid exchanged for sea-water; the cork was always returned to the neck of the bottle, sometimes, but not always, in an inverted position.'

First, the shell is made up of a tube, coiled round itself, and externally convex. Secondly, it is fortified by a series of ribs and vaultings, disposed in the form of arches and domes on the convex surface of this tube, and still further adding to its strength. Thirdly, the transverse plates that form the air-chambers supply also a continuous succession of supports, extending their ramifications, with many mechanical advantages, beneath those portions of the shell which, being weakest, were most in need of them.

'If the existence of contrivance proves the exercise of mind; and if higher degrees of perfection in mechanism are proof of more exalted degrees of intellect in the Author from whom they proceeded; the beautiful examples which we find in the petrified remains of these chambered shells afford evidence coeval and co-extensive with the mountains wherein they are entombed, attesting the wisdom in which such exquisite contrivances originated, and setting forth the providence and care of the Creator, in regulating the structure of every creature of his hand.'-pp. 345-357.

Ammonites, according to Dr. Buckland, evidently had no inkbags; but belemnites were, without doubt, furnished with them, and they have been recently found in situ, in the same lias which gave up the buried ink-bags of the fossil loligines. Dr. Buckland had, in 1829, publicly noticed the probable connexion of these appendages with the belemnites; but Professor Agassiz first demonstrated that connexion in a specimen now in the cabinet of Miss Philpotts at Lyme. The author's comparison of these naked cephalopods, for such they were, with the nautilus, his notice of their analogies with the other genera of chambered shells --and, indeed, his whole history of this extinct race, are admirable.

Our limits will not permit us to allow much space for the more minute chambered shells which D'Orbigny and others have considered cephalopodous; but which, the recent investigations of Du Jardin, as our author is evidently aware, go far to prove of a different organization. Some idea of the innumerable swarms of these multilocular shells may be gained from the following notice on the nummulite, the genus selected by Dr. Buckland for his observations :

Nummulites are so called from their resemblance to a piece of money-they vary in size from that of a crown piece to microscopic littleness; and occupy an important place in the history of fossil shells, on account of the prodigious extent to which they are accumulated in the later members of the secondary, and in many of the tertiary strata. They are often piled on each other nearly in as close contact as the grains in a heap of corn. In this state they form a considerable portion of the entire bulk of many extensive mountains, e. g. in the tertiary limestones of Verona and Monte Bolca, and in secondary strata of the cretacious formation in the Alps, Carpathians,

and

and Pyrenees. Some of the pyramids, and the sphinx of Egypt, are composed of limestone loaded with nummulites.

It is impossible to see such mountain-masses of the remains of a single family of shells thus added to the solid materials of the globe, without recollecting that each individual shell once held an important place within the body of a living animal; and thus recalling our imagination to those distant epochs when the waters of the ocean which then covered Europe were filled with floating swarms of these extinct mollusks, thick as the countless myriads of beröe and clio borealis that now crowd the waters of the Polar seas.'-pp. 383, 4.

We have selected from Dr. Buckland's illustrations a beautiful hydraulic engine of a former world—one extract more, we think, will be permitted us, to produce a fossil optical instrument of equally perfect adaptation, and we must then unwillingly cease our quotations from this part of the work. It may be necessary to apprise some of our readers that trilobites are extinct crustaceous animals, whose form has never yet been detected among living creatures; though there are several analogies between it and some of the forms of existing crustaceans.* These trilobites are of the most remote antiquity, indeed none have yet been found in any strata more recent than the carboniferous series; and yet we are presented by Dr. Buckland with the following account of the structure of their eyes-an account which could hardly have been more clear or more philosophical, if a living lobster had been the subject:

This point deserves peculiar consideration, as it affords the most ancient, and almost the only example yet found in the fossil world, of the preservation of parts so delicate as the visual organs of animals that ceased to live many thousands, and perhaps millions of years ago. We must regard these organs with feelings of no ordinary kind, when we recollect that we have before us the identical instruments of vision, through which the light of heaven was admitted to the sensorium of some of the first created inhabitants of our planet.

'The discovery of such instruments in so perfect a state of preservation, after having been buried for incalculable ages in the early strata of the transition formation, is one of the most marvellous facts yet disclosed by geological researches; and the structure of these eyes supplies an argument of high importance in connecting together the extreme points of the animal creation. An identity of mechanical arrangements, adapted to the construction of an optical instrument precisely similar to that which forms the eyes of existing insects and crustaceans, affords an example of agreement that seems utterly inexplicable without reference to the exercise of one and the same intelligent creative power.

*Animals breathing by means of branchia or gills, whose bodies are covered with a horny crust. Examples occur on the land, in freshwater, and most abundantly, in the sea. A crab and a lobster are crustaceous animals. The trilobite appears to have been marine.

• Professor