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are the organs of vision, which were compound eyes. The discovery of these eyes of trilobites in so perfect a state of preservation, after having been buried for incalculable ages in the early strata of the earth, is one of the most marvellous facts yet disclosed by geological researches. And 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 inhabitants of our planet.

This very wonderful organ of vision, the Compound Eye, is found in many of the insects and crustaceans of the present day. On the head of a fly, for example, are two large protuberances, one on each side; these are its organs of vision. The whole surface of these prominences is covered with a multitude of small hemispheres, arranged closely and with the utmost regularity. These little hemispheres have each of them a minute transparent convex lens in the middle, each of which has a distinct branch of the optic nerve ministering to it; so that the different lenses may be considered as so many distinct eyes. Of these eyes, the beetle has on each side 3180; the common house-fly 4000; the drone-fly 7000each of which, in all these, is capable of receiving and forming a distinct image of any object that may stand or lie before it. Leuwenhoek, having adjusted the eye of a fly for the purpose, could see distinctly in each of these diminutive lenses, though not larger than the point of the finest needle, the whole steeple of a church, which was 299 feet high, and 750 feet distant; and then

turning it toward a neighboring house, saw through many of these little hemispheres, not only the front of the house, but also the doors and windows, and could discern distinctly whether the windows were open or shut! Such a piece of mechanism transcends all comprehension, and is to be reckoned among the highest and most marvellous of animal organs.-Yet, we find this very organ in all its complexity, beauty and efficiency in the trilobites of the dim and immeasurably remote Silurian Epoch.

The form of each eye in the trilobite was that of the frustum of a cone, or of a circular pyramid with the point cut off. On these circular and tapering prominences were ranged compactly and with the utmost regularity the little facets or lenses, for three-fourths of their circumference; so that where the distinct vision of one eye ceased, that of the other began, and their combined range swept the entire horizon. The number of these lenses in different species varied from four hundred to six thousand, in each eye.-Now, when we find organs of such high complexity and perfection as these, organs as complex and perfect as any now living; and find them, not in few or rare instances, but overspreading the globe, and that at the period, so far as man has been able to discover, which marked the dawn of animal existence on our planet-how clear the voice, and how decisive the testimony of such a fact against the Development idea, that as we travel back in time and approach the commencement of things, animal structures must grow more and more simple, higher organisms must

insensibly fade into lower, until at length nothing is left but the merest embryos of life. We have travelled backward by millions of years, and millions of ages, and now stand at the base of the Great Silurian System, hard by "the foundations of the earth," and behold even here the perfection of animal mechanism-EYES as complex and curious, as beautiful and efficient, as any that rejoice in the sunshine of to-day!

Professor Buckland, of Oxford University, speaking of the trilobite eye, says: "We do not find this instrument passing onwards, as it were, through a series of experimental changes, from more simple into more complex forms; it was created at the very first, in the fulness of perfect adaptation to the uses and condition of the class of creatures, to which this kind of eye has ever been, and is still appropriate."

Having descended through the varied and numberless strata of the four great divisions of the earth's crust, and successively surveyed their fossil inhabitants till we have reached a point where all certain traces of organized existences vanish, we may now retrace our steps and come back to the land and light of the living; and we do so with the full conviction that in all we have seen and examined, there is nothing that can with fairness be construed into a support or countenance of the theory of gradual development; on the contrary, platform after platform of animal remains, throughout our whole descent, has clearly proclaimed the Hand and Counsel of

* Bridgewater Treatise, Vol. VI., p. 304.

the Creator to have been concerned in its production, even to the very last we have noticed.

6. If the Darwinian Theory be true, we ought no. to find any animal forms continuing fixed and unchanged from age to age, and epoch to epoch; but all in a process of variation, more or less rapid, but ceaseless. The very foundation of this hypothesis is, that all living organisms are subject to variation arising from the inheritance of less or more of the peculiarities of two distinct parents; from the scarcity or abundance of food; from the heat or cold, dryness or dampness of climate; from the use or disuse of certain members; from spontaneous differences, and accidental deformities. These various causes, it is said, being in operation through all time and in all regions, every organism and type of organism must be in an unceasing process of change.

Now, is this found to be the fact? Is the theory sustained and confirmed in this particular by the revelations of geology? We again say, No,-and support our answer by quotations on the point from an authority that none will suspect of being biased against Mr. Darwin or against his theory. "There are some groups of animals and plants," says Professor Huxley, "in the fossil world, which have been said to belong to 'persistent types,' because they have persisted, with very little change, indeed, through a very great range of time, while everything about them has changed largely. There are families of fishes whose type of construction has persisted all the way from the carboniferous rock right up to the cretaceous; and others which have lasted through almost

the whole range of the secondary rocks, and from the Lias to the older tertiaries. It is something stupendous this-to consider a genus lasting without essential modifications through all this enormous lapse of time while almost everything else was changed and modified."* The same authority tells us that some few animals that flourished in the remote epoch of the Chalk Formation have come down across all the ages of ages that have since elapsed so identical and unchanged as "not to be even distinguishable from living species. The globigerena of that period is not different from that of the present day; and the same may be said of many other Forami nifera. The Snake's head Lamp-shell (Terebratulina caput Serpentis), which lives in our English seas, abounded in the Chalk Seas."+

"The Shark of the Devonian and Carboniferous forma tions differs no more from existing Sharks than these do from one another."

"The highest living group of reptiles, the Crocodile, is represented at the early part of the Mesozoic epoch, by species identical in the essential characters of their organization with those now living."

Principal Dawson tells us, with regard to Mollusks existing in a sub-fossil state in the Post-pliocene days of Canada, that "after carefully studying about one hundred species, and of some of these, many hundreds of specimens, I have arrived at the conclusion that they are absolutely unchanged." "Here again," he adds, "we

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