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the food which they devoured, and yet, knowing with absolute certainty these points, we hardly dare draw the conclusions which are suggested.

But I will venture to carry out the idea, and fill up in yet greater detail a sketch of the condition of the sea and its inhabitants during this portion of the reptilian epoch.

There were then perhaps existing on or near the land some of those reptiles which I shall describe in the next chapter; and with them were associated some true crocodilians, not much unlike the fresh-water garial inhabiting the Ganges. These, perhaps, might occasionally swim out to sea, and be found in the neighbouring shoals.

But these shoals were alive with myriads of invertebrated animals; and crowds of sharks hovered about, feeding upon the larger forms. There were also numerous other animals, belonging to those remark. able groups which I have attempted to describe in some detail. Imagine then one of these monstrous animals, a Plesiosaurus, some sixteen or twenty feet long, with a small wedge-shaped crocodilian head, a long arched serpent-like neck, a short compact body, provided with four large and powerful paddles, almost developed into hands; an animal not covered with brilliant scales, but with a black slimy skin. Imagine for a moment this creature slowly emerging from the muddy banks, and half walking, half creeping along, making its way towards the nearest water. Arrived at the water, we can understand from its structure that it was likely to exhibit greater energy. Unlike the crocodile tribe, however, in all its proportions, it must have been equally dissimilar in habit. Perhaps,

instead of concealing itself in mud or among rushes, it would swim at once boldly and directly to the attack. Its enormous neck stretched out to its full length, and its tail acting as a rudder, the powerful and frequent strokes of its four large paddles would at once give it an impulse, sending it through the water at a very rapid rate. When within reach of its prey, we may almost fancy that we see it drawing back its long neck as it depressed its body in the water, until the strength of the muscular apparatus with which this neck was provided, and the great additional impetus given by the rapid advance of the animal, would combine to produce a stroke from the pointed head which few living animals could resist. The fishes, including perhaps even the sharks, the larger cuttle-fish, and innumerable inhabitants of the sea, would fall an easy prey to this monster.

But now let us see what goes on in the deeper abysses of the ocean, where a free space is given for the operations of that fiercely carnivorous marine reptile, the Ichthyosaurus. Prowling about at a great depth, where the reptilian structure of its lungs and the bony apparatus of the ribs would allow it to remain for a long time without coming to the air to breathe, we may fancy we see this strange animal, with its enormous eyes directed upwards, and glaring like globes of fire; its length is some thirty or forty feet, its head being six or eight feet long; and it has paddles and a tail like a shark; its whole energies are fixed on what is going on above, where the Plesiosaurus or some giant shark is seen devouring its prey. Suddenly, striking with its short but compact paddles, and obtaining a powerful impetus by flapping

its large tail, the monster darts through the water at a rate which the eye can scarcely follow towards the surface. The vast jaws, lined with formidable rows of teeth, soon open wide to their full extent; the object of attack is approached—is overtaken. With a motion quicker than thought the jaws are snapped together, and the work is done. The monster, becoming gorged, floats languidly near the surface, with a portion of the top of its head and its nostrils visible, like an island covered with black mud, above the water.

Such scenes as these must have been every day enacted during the many ages when the waters of the ocean were spread over what is now land in the eastern hemisphere, and when the land then adjacent provided the calcareous mud now forming the lias.

But a description of such scenes of horror and carnage, enacted at former periods of the earth's history, may perhaps induce some of my readers to question the wisdom that permitted, nay enacted them, and conclude rashly that they are opposed to the ideas we are encouraged to form of the goodness of that Being, the necessary action of whose laws, enforced on all living beings, gives rise to them. By no means, however, is this the case. These very results are perfectly compatible with the greatest wisdom and goodness, and, even according to our limited views of the course of nature, they may be shewn not to involve any needless suffering. To us men, constituted as we are, and looking upon death as a punishment which must be endured, premature and violent destruction seems to involve unnecessary pain. But such is not the law of

nature as it relates to animal life in general.

The very exuberance and abundance of life is at once obtained and kept within proper bounds by this rapacity of some great tribes. A lingering death—a natural decay of those powers which alone enable the animal to enjoy life-would, on the contrary, be a most miserable arrangement for beings not endowed with reason, and not assisting each other. It would be cruelty, because it would involve great and hopeless suffering. Death by violence is to all unreasoning animals the easiest death, for it is the most instantaneous; and therefore, no doubt, it has been ordained that throughout large classes there should be an almost indefinite rate of increase, accompanied by destruction rapid and complete in a corresponding degree, since in this way only the greatest amount of happiness is ensured, and the pain and misery of slow decay of the vital powers prevented. All nature, both living and extinct, abounds with facts proving the truth of this view; and it would be as unreasonable to doubt the wisdom and goodness of this arrangement, as it would be to call in question the mutual adaptation of each part in the great scheme of creation. No one who examines nature for himself, however superficially, can doubt the latter; and no one certainly, who duly considers the laws ordained for the general government of the world, can believe it possible for these laws to have acted without a system of compensation, according to which the vital energies of one tribe serve to prepare food for the development of higher powers in another.



AFTER the termination of that great deposit of calcareous mud, so characteristic of the older part of the middle secondary period, considerable change seems to have taken place in the relative position of land and sea; and, from the abundance of calcareous rock afterwards developed, as well as from the nature of the fossils, it may safely be concluded that these changes involved important alterations in the whole system of organic nature in this part of the world. Referring only to those districts which, being now land, enable us to discover their structure, and drawing our conclusions only from the actual facts that have been determined, we may venture to conclude, that, immediately after the deposit of the lias, the bed of the sea was affected by widely acting earthquake movements, and that tracts of land, more or less extensive, rose up, especially on the northeastern flank of the lias in Yorkshire, in several districts on the continent of Europe, and in the central and eastern portions of North America.

It also appears that these elevations must have alternated with depressions, and that thus a number of islands were formed in a sea of moderate depth,

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