Omphalos: An Attempt to Untie the Geological Knot

by Philip Henry Gosse

PARALLELS AND PRECEDENTS.

(Vertebrate Animals.)

"The organisation of the body at each epoch may be truly said to be the resultant of all the material changes which it has undergone during the preceding periods."—Dr. Carpenter; Human Physiology, p. 903.

The Invertebrata then agree in one story, and that story is the same as what the plants had told us before. Let us try if the Vertebrate creatures bear them out.

From this promontory we can look far down into the clear profundity of the still and smooth sea. What is that large object that plays hither and thither yonder, now shooting ahead, now resting on his oars, now turning on his course, now cutting the surface, now descending to the depths? It is a full-grown Sword-fish, some ten feet long. We are sufficiently near him to discern that he has one short but high dorsal fin, near the head, and a minute one close to the caudal, the whole intermediate region being smooth. But this is a mark of adult age; for in early life this same species is furnished with one long and high dorsal, which is continuous from the occiput to the vicinity of the tail-fin. The remotely divided dorsal here tells of many years of life; but tells deceitfully, for the Sword-fish is but just created.

Ha! the Sword-fish has darted away, like lightning, after a finny victim. See with what doublings and windings he pursues it, and how the terrified prey uses all its powers to escape from its gigantic enemy! Now they near the shore; and now the frightened quarry has leaped out of the sea upon yonder flat shelf of rock, where it lies gasping and floundering, delivered indeed from its pursuer, but only to die by being drowned in the air. We will descend from the cliffs, and look at it.

It is a Gilt-head (Chrysophrys aurata). Life is extinct now; but the brilliant colours and fine metallic reflections are scarcely dimmed—the silvery belly—the azure fins—the sides that gleam like polished steel, inlaid with bands of burnished gold!

I will pluck a scale from this brilliant silvery surface. Its hinder, or free edge, is beset with fine flexible crystalline points, arranged in many successive rows, overlapping each other. The front, or attached edge, is cut in a scolloped pattern, the extremities of undulations that radiate from a common point behind the centre. The whole surface, except the hinder portion that is studded with imbricated points, is covered with an immense multitude of fine concentric lines, which follow the form of the general outline. These are marks of successive increase; for every one of the lines is the margin of a lamina, the aggregation of which makes up the thickness of the scale. The laminæ can be separated by long maceration in water; and then we see that they are laid one on another in regular order, the uppermost being the smallest, and the first formed; the last made, which is the largest, being now in contact with the skin.

SCALE OF GILTHEAD.

Every scale is therefore a document, on which is indelibly written the record of a multitude of processes, all effected in the past history of the fish. The successively deposited laminæ are exactly analogous to those of calcareous substance in the shell of the bivalve;[81] and the evidence is of exactly the same character as what we lately read off from the valve of the Dione. But, just as in that example, too, the overruling fact of recent creation precludes our deduction of time from the evidence, since it proves the development to have been prochronic.

I see yonder a more terrific tyrant of the sea than the Sword-fish. It is the grisly Shark (Carcharodon). How stealthily he glides along, cutting the glittering surface of the sea with his dorsal, and now and then protruding just the tip of the upper lobe of his caudal in the wake of the other! Let us go and look into his mouth; for neither animals nor elements present any impediments to these investigations of ours. Is not this an awful array of knives and lancets? Is not this a case of surgical instruments enough to make you shudder? What would be the amputation of your leg to this row of triangular scalpels, each an inch and a half in diameter? moved, too, by these powerful muscles?

But observe the arrangement of these most formidable teeth. They are not confined to a single row as ours are, but each is succeeded by another lying behind it, that by another, and another, and another,—why, there are a dozen ranks of teeth, lying regularly packed one behind the other. The object of this arrangement is a constant supply of new teeth, as those in use become broken off, or wasted by the sloughing away of the exterior half-ossified crust of the cartilaginous jaw, to which their base is fastened by ligaments. Only one row, the outer one, is in use at once, and this row stands erect; the others lie flat on each other (more and more completely as they recede from the outer row); a reserve of weapons in readiness for use, when those now employed are done with. There is a continual growth of the surface to which the teeth are fastened, from within outwards; so that each of the reserve rows will in turn be brought to the edge of the jaw, when it will be thrown up into the erect position, while the preceding, now turned out of the mouth by the gradual eversion of the surface, sloughs away and disappears as an useless incumbrance. It follows, therefore, that the teeth which we now see erect and threatening, are the successors of former ones that have passed away, and that they were once dormant like those we see behind them.

But perhaps you may say, What evidence is there that these ever had any predecessors? that they were not originally the front rank as they are now? A very fair question.

In the first place, the great size of the tooth indicates maturity; and is in keeping with the dimensions of the animal,—some twenty feet or so,—which are those of an adult, if not a full-grown individual. But adult age implies previous youth and infancy, and a gradual growth from the length of a few inches to this formidable size. The teeth are found in the embryo Shark when not more than a foot long; and it is evident that many successive generations of teeth have passed away between those pristine lancets of a line in diameter, and these of an inch and a half.

But stay; there is a peculiarity in the structure of these present teeth, which surely indicates their place to be far on in the succession. Each is seen to be finely serrated on its two outer edges,—a provision which, of course, makes them more effective dividers of flesh and bone. But this structure is not found in the teeth of young individuals, which up to a period comparatively advanced, have simply cutting edges.

Hence we are compelled by the phenomena to infer a long past existence to this animal, which yet has been called into being within an hour.

On yonder twig sits a beautiful little Tree-frog, which you would be ready to mistake for a leaf of more than usually emerald hue, but for the glittering eye, and the line of yellow edged with purple that passes down the side. Do you notice the frequent gulpings of the throat? Those are the periodic inspirations Of air, by which the creature breathes; for, having no ribs, by means of which to depress, and so to expand, the thoracic cavity, the Frog swallows the air by a voluntary action. These air-gulps afford us another example of the sort of evidence we are searching for; they are so many proofs of a past history. For the Tree-frog has not always swallowed air; there was a period in its life when it had no lungs; when it was an aquatic animal, as exclusively a water-breather as any fish. Fish-like in form it was then, as well as in habit; it was a tadpole with a long compressed muscular tail, and with external gills of several branches, but as destitute of lungs as it was of limbs. Any physiologist, looking at our little green Tree-frog, would pronounce without hesitation on the stages through which it has passed; and would describe with the most perfect confidence the order in which they took place; the gradual absorption of the branchiæ, the development of the lungs, the shrinking up and final disappearance of the tail, the budding forth of the tiny rudimentary limbs, the hinder pair first, then the fore pair, and the subsequent division of their extremities into toes;—the metamorphosis of the little fish into a little batrachian, and the gradual growth and maturation of the latter,—these are facts,—the physiologist would say,—as sure both as to their actuality and as to their order, as that the Frog is a Frog.

Ah! but the physiologist is not aware of a fact, which invalidates all his conclusions based upon experience,—the fact that the little Tree-frog has been created but this very instant.

Hark! that rattling noise is an admonition to us to tread circumspectly. It is the vibration of the horny caudal appendages of a Rattlesnake. And I see the reptile coiled up under yonder shadowing leaf. But our presence is a privileged presence, and so we may handle and examine him with impunity. The organ which produces this sound is composed of a number of hollow horny capsules, each one fitting into the next, in which it is retained loosely by a protuberance of its surface. These, being agitated at the will of the animal, produce that sound which we just now heard. The capsules are developed periodically, one being added to the number already existing every year, until as many as forty are accumulated.[82] This individual, therefore, having five-and-twenty rattles, must be five-and-twenty years old.

This Snake, however, has had no past years; it has had no yesterday. Its existence commenced this hour.

Here crouches, among the thick reeds, the Leviathan of the rivers, the mailed Crocodile. His body, invested with bony ridged plates, that rise into strong serrations along the tail, seems clothed with power; and his long rows of interlocking teeth, unveiled by lips, appear grinning with perpetual rage. An experienced herpetologist would not fail to find many evidences of age in this huge reptile. First of all, he would point to its monstrous size; then to the breadth and massive thickness of the dermal plates. "The head," he would say, "in the ruggedness of its surface, shows the same thing, for in youth it was comparatively smooth; and also in the form of its outline; for in this example its length is double its breadth, whereas in youth, these measurements were nearly equal. These conical teeth, too, are by no means the same individual teeth which existed at first. If you look at the base of one, you will see that it is hollow, and that the sides of this portion are already in process of absorption; that this hollow cone is a sheath for another tooth beneath, which is destined to replace it; as this has itself replaced its predecessor. The large size of the teeth which we see, therefore, which accords with the dimensions of the jaws, is not a condition induced by gradual growth, but by a succession of sloughings and replacements; and hence the present teeth, in their size, point conclusively to others which have preceded them, but which have disappeared."

Yet nothing can be more certain, than that, in this Crocodile, which has been created to-day, the successive teeth thus witnessed to, are but ideal, that is prochronic, teeth; and that all the other indications of the lapse of time, in the development of this individual, are liable to the same exception.

See this solemn, slow-going Tortoise, shut up in his high-domed house of bones. It is the beautiful Testudo pardalis, well named from the plates being elegantly spotted and splashed with black on a pale-yellow ground, like the fur of the panther. This is a rather large individual, and the number of concentric lines on the plates of his armour,—or may I not rather say the tiles wherewith his house is roofed?—is commensurately great. You see what I mean. Each of the angular plates has a small nuclear lamina, not in the centre of the area, for the development has been one-sided, but on the highest part. This was the plate in its earliest form, or at least the earliest of which any trace is left; for probably there were others yet earlier and smaller, which, on account of their thinness, have been rubbed away in the travels of the old wanderer. From this nucleus, the plate has been successively enlarged, to correspond with the general growth of the animal, by repeated additions of new laminæ to the inferior surface; each new lamina being a little wider in every direction than that which preceded it, though not equally on all the margins; and thus the plates assumed the form of a very low cone, as you see, always preserving the specific outline, and manifesting the stages of increase, by the projecting edges of the successive laminæ, exactly as we saw lately in the scales of the fish.

PLATES OF TORTOISE.

Whether these laminæ are increased in an annual ratio, I am not sure, nor is it important. There are, I find, about forty-five concentric lines on one plate in this specimen, besides others which are evanescent. Hence it would be quite legitimate to infer that this Tortoise has passed through at least forty-five distinct periods of life, each of which has left a legible record of its existence.

And yet, this moment, in which we look at it, is the very first moment of its life; the concentric layers are evidences of processes that never occurred, except prochronically.

See yonder stately bird, nearly of the height of man, marching among the luxuriant musa-groves, and feeding on the succulent fruits. There is nothing very admirable in its coarse, black, hair-like plumage; but the rich hues of its naked neck, azure, purple, and scarlet, of the most vivid intensity, attract the gaze. The most remarkable feature in its physiognomy, is the singular, tall ridge of horn on its head, which, like the crested helmet of some mailed warrior, imparts an air of martial prowess to the bird, little in accordance with its peaceful habits.

This protuberance is altogether a development of age. The skull, in the youth of the Cassowary, was scarcely more elevated than that of a chicken; but in the lapse of years, the bony ridge, encased in horn, has gradually elevated itself to the height which it now possesses.

Here again we have a record of time, which is belied by the fact of the bird's recent creation.

What is the glorious train of the Peacock, all filled with eyes, but a false witness of the same kind? It leads us to infer that the bird is three years old at least, since before that period, the covert feathers, which are to form the splendid ornament of maturity, are not developed.

What are the lengthened tail-plumes of most refulgent blue, that adorn the Fork-tailed Humming-bird (Trochilus forficatus); what the gorgeously golden tail of the Resplendent Trogon; what the elegant lyre-shaped feathers of the Menura; what the lustrous plumage of the Birds of Paradise,—all of which have been but this hour created,—but so many testimonies, unworthy of confidence, to a past history?

But, further, every individual feather of this beautiful array of plumage concurs in bearing its unblushing witness to the same untruth. What says the physiologist, who is able to read off these autographic records?

GROWTH OF A FEATHER.

"A little while ago, the tips of these feathers were seen each protruding from the extremity of a thick, opaque tube; and a little while before that, the tube itself, was a closed capsule, imbedded in a deep follicle of the skin. If you had then cut open the capsule, you would have found two concentric membranous tubes investing a highly vascular secreting pulp, abundantly supplied with nerves and blood-vessels through an orifice at the bottom of the capsule, and destined to form the substance of the coming feather. Indeed, you would have seen the soft, newly-formed barbs folded round the central organized matrix; and below, the incipient quill, filled with the living pulp-cells, and their blood-vessels, which were destined subsequently to wither up and collapse into the light skinny pith which you see in the perfectly matured feather. These are stages which each of these hundreds of feathers has passed through; and these are but a single generation, which have replaced former series that have been lost in the process of moulting, every one of which had in its turn passed through exactly corresponding stages, and so on backward, till we reach the first race of feathers, which were already partly developed when the chick burst forth from its imprisoning egg-shell."

So says the physiologist; but is he not most egregiously in error, since this is the day of these lovely beings' creation?

There goes the great Whale, the true Whalebone Whale, rolling and wallowing in the trough of the sea, and exposing his enormous black back like an island amidst the white foam, which he stirs up, "making the deep to be hoary." We will use our privilege and take a peep into his mouth, as we did just now into that of the Shark.

What a cavern! and all bristling with long black hair! Why it seems as if the hair grew on the wrong side of his head—on the inside instead of the outside!

Nay, what you call hair is really the Whale's teeth, or what represents teeth. This is the interior free fibrous margin of the baleen, which descends in long triangular plates from the upper jaw. There are about two hundred plates on each side, set face to face, with an interval between, and the edges outward. The inward edge runs off into those long hair-like filaments, which also extend from the slender tip. And the whole forms an effective sifting apparatus, by which the volume of sea-water, which the huge creature takes into his mouth in feeding, is drained of the sea-blubbers, the worms, the mollusks, and other small matters, which constitute the subsistence of this vast body.

Now each of these four hundred plates, some twelve feet in length, has grown from a minute sort of bud, in the upper jaw. Its base is hollow, resting on the formative pulp which is developed from the gum. The pulp is understood to be the immediate origin of the hairy fringe, while a dense vascular substance, seated between the bases of the plates, forms the plate itself. When the plate reaches a certain length, its diameter has become greatly attenuated, and its tip is constantly breaking away, leaving the hair projecting. There is therefore a continual disappearance of the substance of the plates at the tips, and a continual growth at the base to supply the deficiency; and even more, at least during the period of adolescence, because the actual dimensions of the plates have to be increased in the ratio of the growth of the whole animal.

Here, again, we read a record of past history. The Whale is known to be a long-lived animal; and a period of many years must have passed in bringing these plates of baleen to their present maturity. Yet the vast organism before us has been created in its vastness but to-day.

On the most prominent shelf of yonder precipice, a sharp buttress of naked limestone, stands an Ibex, guarding, like a watchful sentinel, the herd in the sheltered valley which own his leadership. The pair of noble horns, which are at once his defence and his pride, are marked throughout their ample curve with semi-rings, or knobs, on their anterior side. These afford us an infallible criterion of the animal's age.

We can count in this Ibex fourteen of such prominent bosses. Now the horn in these animals is not shed during life, but consists of a persistent sheath of horny substance, enveloping a bony core. Until full adult age, both the core of bone and the sheath of horn are continually growing; and in the spring, when there is an unusual augmentation of vital energy in the system, the increase is more than usually rapid. At this season, the new matter deposited in the corneous sheath accumulates in the form of one of these bosses, each of which is therefore produced at the interval of a year. As the first boss appears in the second year of the animal's age, we have but to add one to the number of the bosses on each horn, and we have the number of years which it has lived. The Ibex before us is just fifteen years old.

HORNS OF STAG;
In their successive developments.

Yon Stag that is rubbing his branchy honours against a tree in the glade,—can we apply the same criterion to him? Not exactly: for the horns of all the Deer-tribe are of a different structure from those of the Capradæ. They are bones of great solidity, not invested with any corneous sheath, but clothed for a certain portion of their duration with a living vascular skin, and are shed every year during life and as constantly renewed.

Yet the bony horns of the Stag are no less sure a criterion of age, at least up to a certain period—than are those of the hollow-horned Ibex. In the spring of the second year of the Fawn, the horns first appear, seated on bony footstalks that spring from the frontal bone. The skin that covers these knobs begins to swell and to become turgid with blood supplied by enlarging arteries. Layers of bone are now deposited, particle by particle, on the footstalks, with surprising rapidity, producing the budding horns, which grow day by day, still covered by the skin, which grows also in a corresponding ratio. This goes on till a simple rod of bone is formed, without any branches. When this is complete, the course of the arteries that supplied the skin is cut off by fresh osseous particles deposited in a thick ring around the base. The enveloping skin then dies, and is soon rubbed off.

After a few months, the connexion of the now dead bone with the living is dissolved by absorption, and the horns fall off.

The next spring they are renewed again, but now with a branch or antler; and the whole falls again in autumn. Every spring sees them renewed, but always with an increase of development; and this increase is definite and well-known; so that the age of a Stag, at least of one in the vigour of life, can be readily and certainly stated.

For example, the individual Stag before us, now browsing so peacefully, has each horn composed of the following elements:—the beam, or main stem; two brow-antlers; one stem-antler, and a coronet of four snags, or royal-antlers, at the summit. This condition is peculiar to the seventh development, to which if we add one year for the hornless stage of fawnhood, we obtain eight years, as, beyond all doubt, the age of this Stag.

Both of these examples, however, the Ibex and the Stag, though so conclusive, and seemingly so irrefragable, are rendered nugatory by the opposing fact of a just recent creation.

See this Horse, a newly created, really wild Horse,

"Wild as the wild deer, and untaught,
With spur and bridle undefiled,"—

his sleek coat of a dun mouse-colour, with a black stripe running down his back, and with a full black mane and tail. He has a wild spiteful glance; and his eye, and his lips now and then drawn back displaying his teeth, indicate no very amiable temper. Still, we want to look at those teeth of his. Please to moderate your rancour, generous Dobbin, and let us make an inspection of their condition!

Now notice these peculiarities. The third pair of permanent incisors have appeared, and have attained the same level as their fellows; all are marked with a central hollow on the crown, the middle pair faintly: the canines have acquired considerable size; they present a regularly-convex surface outwardly, without any marks of grooving on the sides; their inner side is concave; their edges sharp; the third permanent molar has displaced its predecessor of the milk set, and the sixth is developed.[83]

This condition of the teeth infallibly marks the fifth year of the Horse's age. A year ago the third incisor was only just rising; the canines were small, and strongly grooved, and the third milk grinder was yet existing. A year hence, the central incisors will be worn quite flat, and their marks obliterated; the canines will be fully grown tusks, the second molar will have reached its full height, and all the teeth will be of the same level. We can then with perfect confidence assert this to be a five-year old Horse. And yet, if we do so, we shall assert a palpable untruth, for the young and vigorous stallion has been created to-day.

SKULL OF BABIROUSSA.

In the thickets of this nutmeg grove beside us there is a Babiroussa; let us examine him. Here he is, almost submerged in this tepid pool. Gentle swine with the circular tusk, please to open your pretty mouth! Here are four incisors in the upper jaw; at one time there were six. The canines of the same jaw having pierced through the flesh and skin of the face, have grown upward and curved backward like horns; nay, they have nearly completed a circle, and are threatening to re-enter the skull; once these tusks had not broken from the gums. There are two pre-molars: once there were four. There are three molars, of which the first is worn quite smooth: once this surface was crowned with four cones; but the third molar had not then appeared.

Away to a broader river. Here wallows and riots the huge Hippopotamus. What can we make of his dentition? A strange array of teeth, indeed, is here; as uncouth and hideous a set as you may hope to see. Yes, but the group is instructive. We will take them in detail.

Look at the lower jaw first. Here are two large projecting incisors in the middle, with their tips worn away obliquely on the outer side, by the action of their opponents in the upper jaw, which are also worn inwardly. The outer incisors, both above and below, are also mutually worn in like manner. The lower canines form massive tusks, curved in the arc of a circle, ground away obliquely by the upper pair; which are short and similarly worn on their front edges. There are three pre-molars on each side, below and above, much worn: once there was a fourth, but it was shed early. Lastly, we find three molars, whose crowns are ground down so as to expose two polished areas of a four-lobed figure. A little while ago, these double areas were trilobate, but at first there were no smooth areas at all; for these are but sections, more or less advanced, of the conical knobs, with which the crown of the molar was originally armed.[84]

In both these examples, the polished surfaces of the teeth, worn away by mutual action, afford striking evidence of the lapse of time. Some one may possibly object, however, to this: "What right have you to assume that these teeth were worn away at the moment of its creation, admitting the animal to have been created adult? May they not have been entire?" I reply, Impossible: the Hippopotamus's teeth would have been perfectly useless to him, except in the ground-down condition: nay, the unworn canines would have effectually prevented his jaws from closing, necessitating the keeping of the mouth wide open until the attrition was performed; long before which, of course, he would have starved. In a natural condition the mutual wearing begins as soon as the surface of the teeth come into contact with each other; that is, as soon as they have acquired a development which constitutes them fit for use. The degree of attrition is merely a question of time. There is no period that can be named, supposing the existence of the perfected teeth at all, in which the evidence of this action would not be visible. How distinct an evidence of past action, and yet, in the case of the created individual, how illusory!

SKULL OF HIPPOPOTAMUS.

"Trampling his path through wood and brake,
And canes, which, crackling, fall before his way,
And tassel-grass, whose silvery feathers play
O'ertopping the young trees,—
On comes the Elephant, to slake
His thirst at noon, in yon pellucid springs.
Lo! from his trunk upturn'd, aloft he flings
The grateful shower: and now
Plucking the broad-leaf'd bough
Of yonder plane, with waving motion slow,
Fanning the languid air,
He waves it to and fro."

We will not be content with admiring the vast size of the fine Dauntelah, and the majesty of his air and movement, and the intelligence manifested in all the actions of the "half-reasoning" beast, as he explores the amœnities of the young world to which he has but this morning been introduced. We are out on another sort of scent: let us try if we can glean any light from him on our present question.

And, first, we cannot fail to notice his fine pair of tusks curving upwards almost to a semicircle. Each tusk is composed of a vast number of thin cones of ivory, superimposed one on another; ever increasing by new ones formed within the interior at the base, and moulded upon the vascular pulp which fills the cavity, and by which the solid ivory is constantly secreted and deposited. Each new cone pushes further and further out those previously deposited, and thus the tusk ever grows in length as it increases in age.

SKULL OF ELEPHANT.

How many years have these tusks occupied in attaining their present diameter and length? We cannot tell: without a transverse section we cannot determine the number of layers of which each consists: and if we could, we should yet require to know what ratio exists between the deposition of a cone of ivory and a fixed period of time. The cones, however, in a tusk of these dimensions, are very numerous, for they are but thin; and it is enough for our purpose that they have occupied the same number of periods of time for their formation, though we cannot precisely indicate the length of these periods.

Leaving the tusks, which are the upper incisors, let us now examine the molars. And there is in these a remarkable peculiarity of development, which will assist us greatly in our chronic inquiries. Before we look at them it may be as well to consider this peculiarity.

The Elephant has, from first to last, six, or perhaps eight, molars on each side of each jaw; but there are never more than two partially, or one wholly, in use at once. They have originally an uneven surface, produced by the extremities of a number of what may be considered as so many finger-like constituent teeth, arranged in transverse rows, covered by hard enamel, and cemented together by a bony substance. These points are gradually worn down by the process of mastication, and then the compound tooth appears crossed by narrow cartouches, or long ovals of enamel, indented at their margins.

"The first set of molars, [i. e. the first compound molar] or milk teeth, begins to cut the jaw eight or ten days after birth, and the grinders of the upper jaw appear before those of the lower one. These milk-grinders are not shed, but are gradually worn away during the time the second set are coming forward; and as soon as the body of the grinder is nearly worn away, the fangs begin to be absorbed. From the end of the second to the beginning of the sixth year, the third set come gradually forward as the jaw lengthens, not only to fill up this additional space, but also to supply the place of this second set, which are, during the same period, gradually worn away, and have their fangs absorbed. From the beginning of the sixth to the end of the ninth year, the fourth set of grinders come forward to supply the gradual waste of the third set. In this manner to the end of life, the Elephant obtains a set of new teeth, as the old ones become unfit for the mastication of its food.

"The milk-grinders consist each of four teeth, or laminæ; the second set of grinders of eight or nine laminæ; the third set of twelve or thirteen; the fourth set of fifteen, and so on to the seventh or eighth set, when each grinder consists of twenty-two or twenty-three: and it may be added, that each succeeding grinder takes at least a year more than its predecessor to be completed."[85]

As each tooth advances, only a small portion pierces the gum at once; one of twelve or fourteen laminæ, for instance, shows only two or three of these through the gum, the remainder being as yet imbedded in the jaw; and in fact the tooth is complete at its fore part, where it is required for mastication, while behind it is still very incomplete; the laminæ are successively perfected as they advance. The molar of an Elephant can never, therefore, be seen in a perfect state: for if it is not worn in front, the back part is not fully formed and is without fangs; and when the structure of the hinder portion is perfected, the front part is already gone.

"When the complex molar cuts the gum, the cement is first rubbed off the digital summits; then their enamel cap is worn away, and the central dentine comes into play with a prominent enamel ring; the digital processes are next ground down to their common uniting base, and a transverse tract of dentine, with its wavy border of enamel, is exposed; finally, the transverse plates themselves are abraded to their common base of dentine, and a smooth and polished tract of that substance is produced. From this basis the roots of the molar are developed, and increase in length, to keep the worn crown on the grinding level, until the reproductive force is exhausted. When the whole extent of a grinder has thus successively come into play, its last part is reduced to a long fang supporting a smooth and polished field of dentine, with sometimes a few remnants of the bottom of the enamel folds at its hinder part. Then, having become useless, it is attacked by the absorbent action, by which, and the pressure of the succeeding tooth, it is finally shed."[86]

With these physiological facts ascertained, let us proceed to the determination of the actual age of our noble Dauntelah. The molar in present use has a length of about nine inches, and a diameter of three and a half. Its crown is crossed by about eighteen enamel-plates; of which the anterior ones are much worn away, while the hinder ones can scarcely be counted with precision, as they have not wholly cut their way through the gum. These characters indicate the fifth molar (or set of molars) of the whole life-series. And the following facts will help us now to fix the actual age, at least approximately.

The first molar cuts the gum at two weeks old, is in full use at three months, and is shed in the course of the second year. The second cuts the gum at about six months, and is shed in the fifth year. The third appears at two years, is in full use about the fifth year, and finally disappears about the ninth year. In the sixth year the fourth breaks from the gum, and lasts till the animal's twenty-fifth year. The fifth cuts the gum at the twentieth year, is entirely exposed soon after the fortieth, and is thrust out about the sixtieth year, by the advance of the sixth molar, which appears at about fifty years old, and probably lasts for half a century more. If others succeed this,—a seventh and even an eighth, as some assert,—these would carry on the Elephant's life to two or three centuries, in accordance with an ancient opinion, which is in some degree countenanced by modern observations.

To come back, then, to the case before us, since the fifth molar has its fore part much worn, and the posterior laminæ scarcely yet protruded from the gum, it follows that this Elephant is now not far from the fortieth year of his life, a deduction which well agrees with the dimensions of his tusks, and his appearance of mature vigour.

Can you detect a flaw in this reasoning? And yet how baseless the conclusion, which assigns a past existence of forty years to a creature called into existence this very day.

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