Lecture Second The Palæontological History of Animals
Amid the unceasing change and endless variety of nature there occur certain great radical ideas, that, while they form, if I may so express myself, the groundwork of the change,—the basis of the variety,—admit in themselves of no change or variety whatever. They constitute the aye-enduring tissue on which the ever-changing patterns of creation are inscribed: the patterns are ever varying; the tissue which exhibits them for ever remains the same. In the animal kingdom, for instance, the prominent ideas have always been uniform. However much the faunas of the various geologic periods may have differed from each other, or from the fauna which now exists, in their general aspect and character, they were all, if I may so speak, equally underlaid by the great leading ideas which still constitute the master types of animal life. And these leading ideas are four in number. First, there is the star-like type of life,—life embodied in a form that, as in the corals, the sea-anemones, the sea-urchins, and the star-fishes, radiates outwards from a centre; second, there is the articulated type of life,—life embodied in a form composed, as in the worms, crustaceans, and insects, of a series of rings united by their edges, but more or less moveable on each other; third, there is the bilateral or molluscan type of life,—life embodied in a form in which there is a duality of corresponding parts, ranged, as in the cuttle-fishes, the clams, and the snails, on the sides of a central axis or plane; and fourth, there is the vertebrate type of life,—life embodied in a form in which an internal skeleton is built up into two cavities placed the one over the other; the upper for the reception of the nervous centres, cerebral and spinal,—the lower for the lodgment of the respiratory, circulatory, and digestive organs. Such have been the four central ideas of the faunas of every succeeding creation, except perhaps the earliest of all, that of the Lower Silurian System, in which, so far as is yet known, only three of the number existed,—the radiated, articulated, and molluscan ideas or types. That Omnipotent Creator, infinite in his resources,—who, in at least the details of his workings, seems never yet to have repeated himself, but, as Lyell well expresses it, breaks, when the parents of a species have been moulded, the dye in which they were cast,—manifests himself, in these four great ideas, as the unchanging and unchangeable One. They serve to bind together the present with all the past; and determine the unity of the authorship of a wonderfully complicated design, executed on a groundwork broad as time, and whose scope and bearing are deep as eternity.
The fauna of the Silurian System bears in all its three great types the stamp of a fashion peculiarly antique, and which, save in a few of the mollusca, has long since become obsolete. Its radiate animals are chiefly corals, simple or compound, whose inhabitants may have somewhat resembled the sea-anemones; with zoophites, akin mayhap to the sea-pens, though the relationship must have been a remote one; and numerous crinoids, or stone lilies, some of which consisted of but a sculptured calyx without petals, while others threw off a series of long, flexible arms, that divided and subdivided like the branches of a tree, and were thickly fringed by hair-like fibres. There is great variety and beauty among these Silurian crinoids; and, from the ornate sculpture of their groined and ribbed capitals and slender columns, the Gothic architect might borrow not a few striking ideas.
The difference between the older and newer fashions, as exemplified in the cup-shaped corals, may be indicated in a single sentence. The ancient corals were stars of four rays, or of multiples of four; the modern corals are stars of six rays, or of multiples of six. But though, at a certain definite period,—that during which the great Palæozoic division ended and the Secondary division began—nature, in forming this class of creatures, discarded the number four, and adopted instead the number six, the great leading idea of the star itself was equally retained in corals of the modern as in those of the more ancient type.
The articulata of the Silurian period bore a still more peculiar character. They consisted mainly of the Trilobites,—a family in whose nicely-jointed shells the armorer of the middle ages might have found almost all the contrivances of his craft, anticipated, with not a few besides which he had failed to discover; and which, after receiving so immense a development during the middle and later times of the Silurian period, that whole rocks were formed almost exclusively of their remains, gradually died out in the times of the Old Red Sandstone, and disappeared for ever from creation after the Carboniferous Limestone had been deposited. The Palæontologist knows no more unique family than that of the Trilobites, or a family more unlike any which now exists, or a family which marks with more certainty the early rocks in which they occur. And yet, though formed in a fashion that perished myriads of ages ago, how admirably does it not exhibit the articulated type of being, and illustrate that unity of design which, amid endless diversity, pervades all nature. The mollusca of the Silurians ranged from the high cephalopoda, represented in our existing seas by the nautili and the cuttle-fishes, to the low brachipods, some of whose congeners may still be detected in the terebratula of our Highland lochs and bays, and some in the lingulæ of the southern hemisphere. The cephalopods of the system are all of an obsolete type, that disappeared myriads of ages ago,—a remark which, with the exceptions just intimated, and perhaps one or two others, applies equally to its brachipods; but of at least two of its intermediate families,—the gasteropoda and lamellibranchiata,—several of the forms resemble those of recent shells of the temperate latitudes. In its general aspect, however, the Silurian fauna, antiquely fashioned, as I have said, as became its place in the primeval ages of existence, was unlike any other which the world ever saw; and the absence of the vertebrata, or at least the inconspicuous place which they occupied if they were at all present, must have imparted to the whole, as a group, a humble and mediocre character. It seems to have been for many ages together a creation of molluscs, corals, and Crustacea. At length, in an upper bed of the system, immediately under the base of the Old Red Sandstone, the remains of the earliest known fishes appear, blent with what also appears for the first time,—the fragmentary remains of a terrestrial vegetation. The rocks beneath this ancient bone-bed have yielded, as I have already said, no trace of any plant higher than the Thallogens, or at least not higher than the Zosteracea,—plants whose proper habitat is the sea; but, through an apparently simultaneous advance of the two kingdoms, animal and vegetable,—though of course the simultaneousness may be but merely apparent,—the first land plants and the first vertebrates appear together in the same deposit.
What, let us inquire, is the character of these ancient fishes, that first complete the scale of animated nature in its four master ideas, by adding the vertebrate to the invertebrate divisions? So far as is yet known, they all consist of one well marked order,—that placoidal order of Agassiz that to an internal framework of cartilage adds an external armature, consisting of plates, spines, and shagreen points of solid bone. Either of the two kinds of dog-fishes on our coasts,—the spiked or spotted,—maybe accepted as not inadequate representatives of this order as it now exists. The Port Jackson shark, however,—a creature that to the dorsal spines and shagreen-covered skin of the common dog-fish adds a mouth terminal at the snout, not placed beneath, as in most other sharks, and a palate covered with a dense pavement of crushing teeth,—better illustrates the order as it first appeared in creation than any of our British placoids.
And here let me adduce another and very remarkable instance of the correspondence which obtains between the sequence in which certain classes of organisms were first ushered into being, and the order of classification adopted, after many revisions, by the higher naturalists. Cuvier, with not a few of the ichthyologists who preceded him, arranged the fishes into two distinct series,—the Cartilaginous and Osseous; and these last he mainly divided into the hard or spiny-finned fishes, and the soft or joint-finned fishes. He placed the sturgeon in his Cartilaginous series; while in his soft-finned order he found a place for the Polypterus of the Nile and the Lepidosteus of the Ohio and St. Lawrence. But the arrangement, though it seemed at the time one of the best and most natural possible, failed to meet any corresponding arrangement in the course of geologic history. The place assigned to the class of fishes as a whole corresponded to their place in the Palæontological scale;—- first of the vertebrate division in the order of their appearance, they border, as in the “Animal Kingdom” of the naturalist, on the invertebrate divisions. But it was not until the new classification of Agassiz had ranged them after a different fashion that the correspondence became complete in all its parts. First, he erected the fishes that to an internal cartilaginous skeleton unite an external armature of plates and points of bone, into his Placoid order; next, gathering together a mere handful of individuals from among the various orders and families over which they had been scattered,—the sturgeons from among the cartilaginous fishes, and the lepidosteus and polypterus from among the Clupia or herrings,—he erected into a small ganoid order all the fishes that are covered, whatever the consistency of their skeleton, by a continuous or nearly continuous armor of enamelled bone, or by great bony plates that lock into each other at their edges. Out of the remaining fishes,—those covered with scales of a horny substance, and which now comprise nearly nine tenths of the whole class,—he erected two orders more,—a Ctenoid order, consisting of fishes whose scales, like those of the perch, are pectinated at their lower edges like the teeth of a comb, and a Cycloid order, composed of fishes whose scales, like those of the salmon, are defined all around by a simple continuous margin; and no sooner was the division effected than it was found to cast a singularly clear light on the early history of the class. The earliest fishes—firstborn of their family—seem to have been all placoids. The Silurian System has not yet afforded trace of any other vertebral animal. With the Old Red Sandstone the ganoids were ushered upon the scene in amazing abundance; and for untold ages, comprising mayhap millions of years, the entire ichthyic class consisted, so far as is yet known, of but these two orders. During the times of the Old Red Sandstone, of the Carboniferous, of the Permian, of the Triassic, and of the Oolitic Systems, all fishes, though apparently as numerous individually as they are now, were comprised in the ganoidal and placoidal orders. The period of these orders seems to have been nearly correspondent with the reign, in the vegetable kingdom, of the Acrogens and Gymnogens, with the intermediate classes, their allies. At length, during the ages of the Chalk, the Cycloids and Ctenoids were ushered in, and were gradually developed in creation until the human period, in which they seem to have reached their culminating point, and now many times exceed in number and importance all other fishes. We do not see a sturgeon (our British representative of the ganoids) once in a twelvemonth; and though the skate and dog-fish (our representatives of the placoids) are greatly less rare, their number bears but a small proportion to that of the fishes belonging to the two prevailing orders, of which thousands of boat-loads are landed on our coasts every day.
The all but entire disappearance of the ganoids from creation is surely a curious and not unsuggestive circumstance. In the human family there are races that have long since reached their culminating point, and are now either fast disappearing or have already disappeared. The Aztecs of Central America, or the Copts of the valley of the Nile, are but the inconsiderable fragments of once mighty nations, memorials of whose greatness live in the vast sepulchral mounds of the far West, or in the temples of Thebes or Luxor, or the pyramids of Gizah. But in the rivers of these very countries,—in the Polypterus of the Nile, or the Lepidosteus of the Mississippi,—we are presented with the few surviving fragments of a dynasty compared with which that of Egypt or of Central America occupied but an exceedingly small portion of either space or time. The dynasty of the ganoids was at one time coextensive with every river, lake, and sea, and endured during the unreckoned eons which extended from the times of the Lower Old Red Sandstone until those of the Chalk. I may here mention, that as there are orders of plants, such as the Rosaceæ and the Grasses, that scarce preceded man in their appearance, so there are families of fishes that seem peculiarly to belong to the human period. Of these, there is a family very familiar on our coasts, and which, though it furnishes none of our higher ichthyic luxuries, is remarkable for the numbers of the human family which it provides with a wholesome and palatable food. The delicate Salmonidæ and the Pleuronectidæ,—families to which the salmon and turbot belong,—were ushered into being as early as the times of the Chalk; but the Gadidæ or cod family,—that family to which the cod proper, the haddock, the dorse, the whiting, the coal-fish, the pollock, the hake, the torsk, and the ling belong, with many other useful and wholesome species,—did not precede man by at least any period of time appreciable to the geologist. No trace of the family has yet been detected in even the Tertiary rocks.
Of the ganoids of the second age of vertebrate existence,—that of the Old Red Sandstone,—some were remarkable for the strangeness of their forms, and some for constituting links of connection which no longer exist in nature, between the ganoid and placoid orders. The Acanth family, which ceased with the Coal Measures, was characterized, especially in its Old Red species, by a combination of traits common to both orders; and among the extremer forms, in which Palæontologists for a time failed to detect that of the fish at all, we reckon those of the genera Coccosteus, Pterichthys, and Cephalaspis. The more aberrant genera, however, even while they consisted each of several species, were comparatively short lived. The Coccosteus and Cephalaspis were restricted to but one formation apiece; while the Pterichthys, which appears for the first time in the lower deposits of the Old Red Sandstone, becomes extinct at its close. On the other hand, some of the genera that exemplified the general type of their class were extremely long lived. The Celacanths were reproduced in many various species, from the times of the Lower Old Red Sandstone to those of the Chalk; and the Cestracions, which appear in the Upper Ludlow Rocks as the oldest of fishes, continue in at least one species to exist still. It would almost seem as if some such law influenced the destiny of genera in this ichthyic class, as that which we find so often exemplified in our species. The dwarf, or giant, or deformed person, is seldom a long liver;—all the more remarkable instances of longevity have been furnished by individuals cast in the ordinary mould and proportions of the species. Not a few of these primordial ganoids wore, however, of the highest rank and standing ever exemplified by their class; and we find Agassiz boldly assigning a reason for their superiority to their successors, important for the fact which it embodies, and worthy, as coming from him, of our most respectful attention. “It is plain,” we find him saying, “that before the class of reptiles was introduced upon our globe, the fishes, being then the only representatives of the type of vertebrata, were invested with the characters of a higher order, embodying, as it were, a prospective view of a higher development in another class, which was introduced as a distinct type only at a later period; and from that time the reptilian character, which had been so prominent in the oldest fishes, was gradually reduced, till in more recent periods, and in the present creation, the fishes lost all this herpetological relationship, and were at last endowed with characters which contrast as much, when compared with those of reptiles, as they agreed closely in the beginning. Lepidosteus alone reminds us in our time of these old-fashioned characters of the class of fishes as it was in former days.”
The ancient fishes seem to have received their fullest development during the Carboniferous period. Their number was very great: some of them attained to an enormous size, and, though the true reptile had already appeared, they continued to retain, till the close of the system, the high reptilian character and organization. Nothing, however, so impresses the observer as the formidable character of the offensive weapons with which they were furnished, and the amazing strength of their defensive armature. I need scarce say, that the Palæontologist finds no trace in nature of that golden age of the world, of which the poets delighted to sing, when all creatures lived together in unbroken peace, and war and bloodshed were unknown. Ever since animal life began upon our planet, there existed, in all the departments of being, carnivorous classes, who could not live but by the death of their neighbors, and who were armed, in consequence, for their destruction, like the butcher with his axe and knife, and the angler with his hook and spear. But there were certain periods in the history of the past, during which these weapons assumed a more formidable aspect than at others; and never were they more formidable than in the times of the Coal Measures. The teeth of the Rhizodus—a ganoidal fish of our coal fields—were more sharp and trenchant than those of the crocodile of the Nile, and in the larger specimens fully four times the bulk and size of the teeth of the hugest reptile of this species that now lives. The dorsal spine of its contemporary, the Gyracanthus, a great placoid, much exceeded in size that of any existing fish: it was a mighty spear head, ornately carved like that of a New Zealand chief, but in a style that, when he first saw a specimen in my collection, greatly excited the admiration of Mr. Ruskin. But one of the most remarkable weapons of the period was the sting of the Pleuracanthus, another great placoid of the age of gigantic fishes. It was sharp and polished as a stiletto, but, from its rounded form and dense structure, of great strength; and along two of its sides, from the taper point to within a few inches of the base, there ran a thickly-set row of barbs, hooked downwards, like the thorns that bristle on the young shoots of the wild rose, and which must have rendered it a weapon not merely of destruction, but also of torture. The defensive armor of the period, especially that of its ganoids, seems to have been us remarkable for its powers of resistance as the offensive must have been for their potency in the assault; and it seems probable that in the great strength of the bony and enamelled armature of this order of fishes we have the secret of the extremely formidable character of the teeth, spines, and stings that coexisted along with it.
Such of the fishes of the present time as live on crustacea and the shelled molluscs,—such as the Wrasse or rock-fish family, and at least one of the Goby family, the sea-wolf,—have an apparatus of crushing teeth greatly more solid and strong than the teeth of such of their contemporaries as are either herbivorous or feed on the weaker families of their own class. A similar remark applies to the ancient sharks, as contrasted with those of later times. So long as the strongly-armed ganoidal order prevailed in nature, the sharks were furnished with massive crushing teeth; but when the ganoids waned in creation, and the soft-scaled cycloid and ctenoid orders took and amply filled the place which they had left vacant, the well known modern form of sharks’ teeth was introduced,—a form much rather suited for cutting soft bodies than for crushing hard ones. In fine, the offensive weapons of the times of the Coal Measures seem very formidable, just as those personal weapons of the middle ages seem so that were borne at a time when every soldier took the field cased in armor of proof. The slim scimitar or slender rapier would have availed but little against massive iron helmets or mail coats of tempered steel. And so the warriors of the period armed themselves with ponderous maces, battle-axes as massive as hammers, and double-handed swords of great weight and strength.
Before passing onwards to other and higher classes and orders, as they occurred in creation, permit me to make the formidable armor of the earlier fishes, offensive and defensive, the subject of a single remark. We are told by Goethe, in his autobiography, that he had attained his sixth year when the terrible earthquake at Lisbon took place,—“an event,” he says, “which greatly disturbed” his “peace of mind for the first time.” He could not reconcile a catastrophe so suddenly destructive to thousands, with the ideas which he had already formed for himself of a Providence all-powerful and all-benevolent. But he afterwards learned, he tells us, to recognize in such events the “God of the Old Testament.” I know not in what spirit the remark was made; but this I know, that it is the God of the Old Testament whom we see exhibited in all nature and all providence; and that it is at once wisdom and duty in his rational creatures, however darkly they may perceive or imperfectly they may comprehend, to hold in implicit faith that the Adorable Monarch of all the past and of all the future is a King who “can do no wrong.” This early exhibition of tooth, and spine, and sting,—of weapons constructed alike to cut and to pierce,—to unite two of the most indispensable requirements of the modern armorer,—a keen edge to a strong back,—nay, stranger still, the examples furnished in this primeval time, of weapons formed not only to kill, but also to torture,—must be altogether at variance with the preconceived opinions of those who hold that until man appeared in creation, and darkened its sympathetic face with the stain of moral guilt, the reign of violence and outrage did not begin, and that there was no death among the inferior creatures, and no suffering. But preconceived opinion, whether it hold fast, with Lactantius and the old Schoolmen, to the belief that there can be no antipodes, or assert, with Caccini and Bellarmine, that our globe hangs lazily in the midst of the heavens, while the sun moves round it, must yield ultimately to scientific truth. And it is a truth as certain as the existence of a southern hemisphere, or the motion of the earth round both its own axis and the great solar centre, that, untold ages ere man had sinned or suffered, the animal creation exhibited exactly its present state of war,—that the strong, armed with formidable weapons, exquisitely constructed to kill, preyed upon the weak; and that the weak, sheathed, many of them, in defensive armor equally admirable in its mechanism, and ever increasing and multiplying upon the earth far beyond the requirements of the mere maintenance of their races, were enabled to escape, as species, the assaults of the tyrant tribes, and to exist unthinned for unreckoned ages. It has been weakly and impiously urged,—as if it were merely with the geologist that men had to settle this matter,—that such an economy of warfare and suffering,—of warring and of being warred upon,—would be, in the words of the infant Goethe, unworthy of an all-powerful and all-benevolent Providence, and in effect a libel on his government and character. But that grave charge we leave the objectors to settle with the great Creator himself. Be it theirs, not ours, according to the poet, to
“Snatch from his hand the balance and the rod,
Rejudge his justice, be the god of God.”
Be it enough for the geologist rightly to interpret the record of creation,—to declare the truth as he finds it,—to demonstrate, from evidence no clear intellect ever yet resisted, that he, the Creator, from whom even the young lions seek their food, and who giveth to all the beasts, great and small, their meat in due season, ever wrought as he now works in his animal kingdom,—that he gave to the primeval fishes their spines and their stings,—to the primeval reptiles their trenchant teeth and their strong armor of bone,—to the primeval mammals their great tusks and their sharp claws,—that he of old divided all his creatures, as now, into animals of prey and the animals preyed upon,—that from the beginning of things he inseparably established among his non-responsible existences the twin laws of generation and of death,—nay, further, passing from the established truths of Geologic to one of the best established truths of Theologic science,—God’s eternal justice and truth,—let us assert, that in the Divine government the matter of fact always determines the question of right, and that whatever has been done by him who rendereth no account to man of his matters, he had in all ages, and in all places, an unchallengeable right to do.
The oldest known reptiles appear just a little before the close of the Old Red Sandstone, just as the oldest known fishes appeared just a little before the close of the Silurian System. What seems to be the Upper Old Red of our own country, though there still hangs a shade of doubt on the subject, has furnished the remains of a small reptile, equally akin, it would appear, to the lizards and the batrachians; and what seems to be the Upper Old Red of the United States has exhibited the foot-tracks of a larger animal of the same class, which not a little resemble those which would be impressed on recent sand or clay by the alligator of the Mississippi, did not the alligator of the Mississippi efface its own footprints (a consequence of the shortness of its legs) by the trail of its abdomen. In the Coal Measures, the reptiles hitherto found,—and it is still little more than ten years since the first was detected,—are all allied, though not without a cross of the higher crocodilian or lacertian nature, to the batrachian order,—that lowest order of the reptiles to which the frogs, newts, and salamanders belong. These reptiles of the carboniferous era, though only a few twelvemonths ago we little suspected the fact, seem to have been not very rare in our own neighborhood. My attention was called some time since by Mr. Henry Cadell,—an intelligent practical geologist,—to certain appearances in one of the Duke of Buccleuch’s coal pits near Dalkeith, which lie regarded as the tracks of air-breathing quadrupeds; and, after examining a specimen, containing four footprints, which he had brought above ground, and which not a little excited my curiosity, we visited the pit together. And there, in a side working about half a mile from the pit mouth, and about four hundred feet under the surface, I found the roof of the coal, which rose at a high angle, traversed by so many foot-tracks, upwards, downwards, and athwart, that it cost me some little care to trace the individual lines. At least one of the number, however,—consisting of eleven footprints of the right and as many of the left foot—I was able to trace from side to side of the working, a distance of four yards; and several of the others for shorter spaces. The prints, which were reverses or casts in a very coarse sandstone, were about thirtecn inches apart across the creature’s chest, and rather more than a foot apart from its fore to its hinder limbs. They were alternately larger and smaller,—the smaller (those of the fore feet) measuring about four inches in length, and the larger (those of the hinder feet) about six inches. The number of toes seemed to be alternately four and five; but from the circumstance that the original matrix on which the tracks had been impressed,—a micaceous clay resolved into a loose fissile sandstone,—had fallen away in the working of the pit, leaving but the boldly-relieved though ill-defined casts on the coarse sandstone, I could not definitely determine the point. Enough, however, remained to show that at that spot,—little more than a mile from where the Duke of Buccleuch’s palace now stands,—large reptiles had congregated in considerable numbers shortly after the great eight feet coal seam of the Dalkeith basin had been formed. In another part of the pit I found foot-tracks of apparently the same animal in equal abundance, but still less distinct in their state of keeping. But they bore testimony with the others to the comparative abundance of reptilian life at an early period, when the coal-bearing strata of the empire were little more than half deposited. It was not, however, until the Permian and Triassic Systems had come to a close, and even the earlier ages of the Oolitic System had passed away, that the class received its fullest development in creation. And certainly very wonderful was the development which it then did receive. Reptiles became everywhere the lords and masters of this lower world. When any class of the air-breathing vertebrates is very largely developed, we find it taking possession of all the three old terrestrial elements,—earth, air, and water. The human period, for instance, like that which immediately preceded it, is peculiarly a period of mammals; and we find the class, free, if I may so express myself, of the three elements, disputing possession of the sea with the fishes, in its Cetaceans, its seals, and its sea-lions, and of the air with the birds, in its numerous genera of the bat family. Further, not until the great mammaliferous period is fairly ushered in do either the bats or the whales make their appearance in creation. Remains of Oolitic reptiles have been mistaken in more than one instance for those of Cetacea; but it is now generally held that the earliest known specimens of the family belong to the Tertiary ages, while those of the oldest bats occur in the Eocene of the Paris Basin, associated with the bones of dolphins, lamantines, and morses. Now, in the times of the Oolite it was the reptilian class that possessed itself of all the elements. Its gigantic enaliosaurs, huge reptilian whales mounted on paddles, were the tyrants of the ocean, and must have reigned supreme over the already reduced class of fishes; its pterodactyles,—dragons as strange as were ever feigned by romancer of the middle ages, and that to the jaws and teeth of the crocodile added the wings of a bat and the body and tail of an ordinary mammal, had “the power of the air,” and, pursuing the fleetest insects in their flight, captured and bore them down;14 its lakes and rivers abounded in crocodiles and fresh water tortoises of ancient type and fashion; and its woods and plains were the haunts of a strange reptilian fauna, of what has been well termed “fearfully great lizards,”—some of which, such as the iguanodon, rivalled the largest elephant in height, and greatly more than rivalled him in length and bulk. Judging from what remains, it seems not improbable that the reptiles of this Oolitic period were quite as numerous individually, and consisted of well nigh as many genera and species, as all the mammals of the present time. In the cretaceous ages, the class, though still the dominant one, is visibly reduced in its standing; it had reached its culminating point in the Oolite, and then began to decline; and with the first dawn of the Tertiary division we find it occupying, as now, a very subordinate place in creation. Curiously enough, it is not until its times of humiliation and decay that one of the most remarkable of its orders appears,—an order itself illustrative of extreme degradation, and which figures largely, in every scheme of mythology that borrowed through traditional channels from Divine revelation, as a meet representative of man’s great enemy the Evil One. I of course refer to the ophidian or serpent family. The earliest ophidian remains known to the Palæontologist occur in that ancient deposit of the Tertiary division known as the London Clay, and must have belonged to serpents, some of them allied to the Pythons, some to the sea-snakes, which, judging from the corresponding parts of recent species, must have been from fourteen to twenty feet in length.
And here let us again pause for a moment, to remark how strangely these irascible, repulsive reptiles,—creatures lengthened out far beyond the proportions of the other members of their class by mere vegetative repetitions of the vertebræ,—condemned to derive, worm-like, their ability of progressive motion from the ring-like scutes of the abdomen—venomous in many of their species,—formidable in others to even the noblest animals, from their fascinating powers and their great craft,—without, fore or hinder limbs, without thoracic or pelvic arches,—the very types and exemplars (our highest naturalists being the judges) of the extreme of animal degradation,—let us, I say, remark how strangely their history has been mixed up with that of man and of religion in all the older mythologies, and in that Divine Revelation whence the older mythologies were derived. It was one of the most ancient of the Phœnician fables, that the great antagonist of the gods was a gigantic serpent, that had at one time been their subject, but revolted against them and became their enemy. It was a monstrous serpent that assailed and strove to destroy the mother of Apollo ere yet the birth of the god, but which, long after, Apollo in turn assaulted and slew. It was a great serpent that watched over the apples of the Hesperides, and that Hercules, ere he could possess himself of the fruit, had to combat and kill. It was a frightful serpent that guarded the golden fleece from Jason, and which the hero had to destroy in the first instance, and next to exterminate the strange brood of armed men that sprang up from its sown teeth. In short, the old mythologies are well nigh as full of the serpent as those ancient Runic obelisks of our country, whose endless knots and complicated fretwork are formed throughout of the interlacings of snakes. Let us, however, accept as representative of this innumerable class of legends, the classical story, rendered yet more classical by the profound and reverend comment given by Bacon in his “Wisdom of the Ancients.” “Jupiter and the other gods,” says the philosopher, in his simple version of the tradition, “conferred upon men a most acceptable and desirable boon,—the gift of perpetual youth. But men, foolishly overjoyed hereat, laid this present of the gods upon an ass, who, in returning back with it, being extremely thirsty, and coming to a fountain, the serpent who was guardian thereof would not suffer him to drink but upon condition of receiving the burden he carried, whatever it should be. The silly ass complied; and thus the perpetual renewal of youth was for a sup of water transferred from men to the race of serpents.” “That this gift of perpetual youth should pass from men to serpents,” continues Bacon, “seems added, by way of ornament and illustration, to the fable.” And it certainly has much the appearance of an after-thought. But how very striking the resemblance, borne by the story, as a whole, to that narrative in the opening page of human history which exhibits the first parents of the race as yielding up to the temptation of the serpent the gift of immortality; and further, how remarkable the fact, that the reptile selected as typical here of the great fallen spirit that kept not his first estate, should be at once the reptile of latest appearance in creation, and the one selected by philosophical naturalists as representative of a reversed process in the course of being,—of a downward, sinking career, from the vertebrate antetype towards greatly lower types in the invertebrate divisions! The fallen spirit is represented in revelation by what we are now taught to recognize in science as a degraded reptile.
Birds make their first appearance in a Red Sandstone deposit of the United States in the valley of the Connecticut, which was at one time supposed to belong to the Triassic System, but which is now held to be at least not older than the times of the Lias. No fragments of the skeletons of birds have yet been discovered in formations older than the Chalk: the Connecticut remains are those of footprints exclusively; and yet they tell their extraordinary story, so far as it extends, with remarkable precision and distinctness. They were apparently all of the Grallæ or stilt order of birds,—an order to which the cranes, herons, and bustards belong, with the ostriches and cassowaries, and which is characterized by possessing but three toes on each foot (one species of ostrich has but two), or, if a fourth toe be present, so imperfectly is it developed in most of the cases, that it fails to reach the ground. And in almost all the footprints of the primeval birds of the Connecticut there are only three toes exhibited. Peculiar, ill understood laws regulate the phalangal divisions of the various animals. It is a law of the human kind, for instance, that the thumb should consist of but three phalanges; while the fingers, even the smallest, consist of four. And, in the same way, it is a law generally exemplified among birds, that of the three toes which correspond to the fingers, the inner toe should be composed of three phalanges, the middle or largest toe of four phalanges, and the outer toe, though but second in point of size, of five phalanges. Such is the law now, and such was equally the law, as shown by the American footprints, in the times of the Lias. Some of the impressions are of singular distinctness. Every claw and phalange has left its mark in the stone; while the trifid termination of the tarso-metatarsal bone leaves three marks more,—fifteen in all,—the true ornithic number. In some of the specimens even the pressure of a metatarsal brush, still possessed by some birds, is distinctly traceable; nay, there are instances in which the impress of the dermoid papillæ has remained as sharply as if made in wax. But the immense size of some of these footprints served to militate for a time against belief in their ornithic origin. The impressions that are but secondary in point of size greatly exceed those of the hugest birds which now exist; while those of the largest class equal the prints of the bulkier quadrupeds. There are tridactyle footprints in the red sandstones of Connecticut that measure eighteen inches in length from the heel to the middle claw, nearly thirteen inches in breadth from the outer to the inner toe, and which indicate, from their distance apart in the straight line, a stride of about six feet in the creature that impressed them in these ancient sands,—measurements that might well startle zoologists who had derived their experience of the ornithic class from existing birds exclusively. Comparatively recent discoveries have, however, if not lessened, at least familiarized us to the wonder. In a deposit of New Zealand that dates little if at all in advance of the human period, there have been detected the remains of birds scarce inferior in size to those of America in the Liassic ages. The bones of the Dinornus giganteus, exhibited by the late Dr. Mantell in Edinburgh in the autumn of 1850, greatly exceeded in bulk those of the largest horse. A thigh bone sixteen inches in length measured nearly nine inches in circumference in the middle of the shaft: the head of a tibia measured twenty-one inches in circumference. It was estimated that a foot entire in all its parts, which formed an interesting portion of the exhibition, would, when it was furnished with nails, and covered by the integuments, have measured about fifteen inches in length; and it was calculated by a very competent authority, Professor Owen, that of the other bones of the leg to which it belonged, the tibia must have been about two feet nine inches, and the femur about fourteen and a half inches long. The larger thigh bone referred to must have belonged, it was held, to a bird that stood from eleven to twelve feet high,—the extreme height of the great African elephant. Such were the monster birds of a comparatively recent period; and their remains serve to render credible the evidence furnished by the great footprints of their remote predecessors of the Lias. The huge feet of the greatest Dinornus whose bones have yet been found would have left impressions scarcely an inch shorter than those of the still huger birds of the Connecticut. Is it not truly wonderful, that in this late age of the world, in which the invention of the poets seems to content itself with humbler and lowlier flights than of old, we should thus find the facts of geology fully rivalling, in the strange and the outré, the wildest fancies of the romancers who flourished in the middle ages? I have already referred to flying dragons,—real existences of the Oolitic period,—that were quite as extraordinary of type, if not altogether so huge of bulk, as those with which the Seven Champions of Christendom used to do battle; and here are we introduced to birds of the Liassic ages that were scarce less gigantic than the roc of Sinbad the Sailor. They are fraught with strange meanings these footprints of the Connecticut. They tell of a time far removed into the by-past eternity, when great birds frequented by myriads the shores of a nameless lake, to wade into its shallows in quest of mail-covered fishes of the ancient type, or long-extinct molluscs; while reptiles equally gigantic, and of still stranger proportions, haunted the neighboring swamps and savannahs; and when the same sun that shone on the tall moving forms beside the waters, and threw their long shadows across the red sands, lighted up the glades of deep forests, all of whose fantastic productions,—tree, bush, and herb,—have even in their very species long since passed away. And of this scene of things only the footprints remain,—“footprints on the sands of time,” that tell us, among other matters, whence the graceful American poet derived his quiet but singularly effective and unmistakeably indigenous figure:—
“Lives of great men all remind us
We can make our lives sublime,
And, departing, leave behind us
Footprints on the sand of time.
Footprints that perhaps another,
Sailing o’er life’s solemn main,
A forlorn and shipwrecked brother,
Seeing, shall take heart again.”
With the Stonisfield slates,—a deposit which lies above what is known as the Inferior Oolite,—the remains of mammaliferous animals first appear. As, however, no other mammalian remains occur until after the close of the great Secondary Division, and as certain marked peculiarities attach to these Oolitic ones, it may be well to inquire whether their place, so far in advance of their fellows, may not be indicative of a radical difference of character,—a difference considerable enough to suggest to the zoologist an improvement in his scheme of classification. It has been shown by Professor Owen,—our highest authority in comparative anatomy,—that while one Stonisfield genus unequivocally belonged to the marsupial order, another of its genera bears also certain of the marsupial traits; and that the group which they composed,—a very small one, and consisting exclusively of minute insect-eating animals,—exhibits in its general aspect the characteristics of this pouched family. Even the genus of the group that least resembles them was pronounced by Cuvier to have its nearest affinities with the opossums. And let us mark how very much may be implied in this circumstance. In the “Animal Kingdom” of the great naturalist just named, the marsupiata, or pouched animals, are made to occupy the fourth place among the nine orders of the Mammalia; but should they not rather occupy a place intermediate between the placental mammals and the birds? and does not nature indicate their true position by the position which she assigns to them in the geologic scale? The birds are oviparous; and between the extrusion of the egg and the development of the perfect young bird they have to hatch it into life during a long period of incubation. The marsupiata are not oviparous, for their eggs want the enveloping shell or skin; but they, too, are extruded in an exceedingly rudimentary and fœtal state, and have to undergo in the pouch a greatly longer period of incubation than that demanded by nature for any bird whatever. The young kangaroo is extruded, after it has remained for little more than a month in the womb, as a foetus scarcely an inch in length by somewhat less than half an inch in breadth: it is blind, exhibiting merely dark eye spots; its limbs are so rudimentary, that even the hinder legs, so largely developed in the genus when mature, exist as mere stumps; it is unable even to suck, but, holding permanently on by a minute dug, has the sustaining fluid occasionally pressed into its mouth by the mother. And, undergoing a peculiar but not the less real process of incubation, the creature that had to remain for little more than a month in the womb,—strictly thirty-nine days,—has to remain in the mother’s pouch, ere it is fully developed and able to provide for itself, for a period of eight months. It is found to increase in weight during this hatching process, from somewhat less than an ounce to somewhat more than eight pounds. Now, this surely is a process quite as nearly akin to the incubation of egg-bearing birds as to the ordinary nursing process of the placental mammals; and on the occult but apparently real principle, that the true arrangement of the animal kingdom is that which we find exemplified by the successive introduction of its various classes and orders in the course of geologic history, should we not anticipate a point of time for the introduction of the marsupiata, intermediate between the widely-distant points at which the egg-bearing birds and the true placental mammals appeared? Ranged at once chronologically, and by their mode of reproduction, the various classes of the vertebrata would run, did we accept the suggested reading, as follows:—First appear cold-blooded vertebrates (fishes), that propagate by eggs or spawn,—chiefly by the latter. Next appear cold-blooded vertebrates (reptiles), that propagate by eggs or spawn,—chiefly by the former. Then appear warm-blooded vertebrates (birds), that propagate by eggs exclusively. Then warm-blooded vertebrates come upon the stage, that produce eggs without shells, which have to be subjected for months to a species of extra-placental incubation. And last of all the true placental mammals appear. And thus, tried by the test of perfect reproduction, the great vertebral division receives its full development in creation.
The placental mammals make their appearance, as I have said, in the earliest ages of the great Tertiary division, and exhibit in the group an aspect very unlike that which they at present bear. The Eocene ages were peculiarly the ages of the Palæotheres,—strange animals of that pachydermatous or thick-skinned order to which the elephants, the tapirs, the hogs, and the horses belong. It had been remarked by naturalists, that there are fewer families of this order in living nature than of almost any other, and that, of the existing genera, not a few are widely separated in their analogies from the others. But in the Palæotheres of the Eocene, which ranged in size from a large horse to a hare, not a few of the missing links have been found,—links connecting the tapirs to the hogs, and the hogs to the Palæotheres proper; and there is at least one species suggestive of an union of some of the more peculiar traits of the tapirs and the horses. It was among these extinct Pachydermata of the Paris basin that Cuvier effected his wonderful restorations, and produced those figures in outline which are now as familiar to the geologist as any of the forms of the existing animals. The London Clay and the Eocene of the Isle of Wight have also yielded numerous specimens of those pachyderms, whose identity with the Continental ones has been established by Owen; but they are more fragmentary, and their state of keeping less perfect, than those furnished by the gypsum quarries of Velay and Montmartre. In these the smaller animals occur often in a state of preservation so peculiar and partial as to excite the curiosity of even the untaught workmen. Only half the skeleton is present. The limbs and ribs of the under side are found lying in nearly their proper places; while of the limbs and ribs of the upper side usually not a trace can be detected,—even the upper side of the skull is often awanting. It-would almost seem as if some pre-Adamite butcher had divided the carcasses longitudinally, and carried away with him all the upper halves. The reading of the enigma seems to be, that when the creatures lay down and died, the gypsum in which their remains occur was soft enough to permit their under sides to sink into it, and that then gradually hardening, it kept the bones in their places; while the uncovered upper sides, exposed to the disintegrating influences, either mouldered away piecemeal, or were removed by accident. The bones of the larger animals of the basin are usually found detached; and ere they could be reconstructed into perfect skeletons, they taxed the extraordinary powers of the greatest of comparative anatomists. Rather more than twenty different species of extinct mammals have been detected in the Paris basin,—not a great number, it may be thought; and yet for so limited a locality we may deem it not a very small one, when we take into account the fact that all our native mammals of Britain and Ireland amount (according to Fleming), if we except the Cetaceæ and the seals, to but forty species.
In the Middle or Miocene Tertiary, pachyderms, though of a wholly different type from their predecessors, are still the prevailing forms. The Dinotherium, one of the greatest quadrupedal mammals that ever lived, seems to have formed a connecting link in this middle age between the Pachydermata and the Cetaceæ. Each ramus of the under jaw, which in the larger specimens are fully four feet in length, bore at the symphysis a great bent tusk turned downwards, which appears to have been employed as a pickaxe in uprooting the aquatic plants and liliaceous roots on which the creature seems to have lived. The head, which measured about three feet across,—a breadth, sufficient, surely, to satisfy the demands of the most exacting phrenologist,—was provided with muscles of enormous strength, arranged so as to give potent effect to the operations of this strange tool. The hinder part of the skull not a little resembled that of the Cetaceæ; while, from the form of the nasal bones, the creature was evidently furnished with a trunk like the elephant. It seems not improbable, therefore, that this bulkiest of mammaliferous quadrupeds constituted, as I have said, a sort of uniting tie between creatures still associated in the human mind, from the circumstance of their massive proportions, as the greatest that swim the sea or walk the land,—the whale and the elephant. The Mastodon, an elephantoid animal, also furnished, like the elephant, with tusks and trunk, but marked by certain peculiarities which constitute it a different genus, seems in Europe to have been contemporary with the Dinotherium; but in North America (the scene of its greatest numerical development) it appears to belong to a later age. In height it did not surpass the African elephant, but it considerably exceeded it in length,—a specimen which could not have stood above twelve feet high indicating a length of about twenty-five feet: it had what the elephants want,—tusks fixed in its lower jaw, which the males retained through life, but the females lost when young; its limbs were proportionally shorter, but more massive, and its abdomen more elongated and slim; its grinder teeth too, some of which have been known to weigh from seventeen to twenty pounds, and their cusps elevated into great mammæ-like protuberances, to which the creature owes its name, and wholly differ in their proportions and outline from the grinders of the elephant. The much greater remoteness of the mastodonic period in Europe than in America is a circumstance worthy of notice, as it is one of many facts that seem to indicate a general transposition of at least the later geologic ages on the opposite sides of the Atlantic. Groups of corresponding character on the eastern and western shores of this great ocean were not contemporaneous in time. It has been repeatedly remarked, that the existing plants and trees of the United States, with not a few of its fishes and reptiles, bear in their forms and construction the marks of a much greater antiquity than those of Europe. The geologist who sets himself to discover similar types on the eastern side of the Atlantic would have to seek for them among the deposits of the later Tertiaries. North America seems to be still passing through its later Tertiary ages; and it appears to be a consequence of this curious transposition, that while in Europe the mastodonic period is removed by two great geologic eras from the present time, it is removed from it in America by only one. Even in America, however, that period lies far beyond the reach of human tradition,—a fact borne out by the pseudo-traditions retailed by the aborigines regarding the mastodon. By none of at least the higher naturalists has there been a doubt entertained respecting its herbivorous character; and the discovery of late years of the stomach of an individual charged with decayed herbage and fragments of the succulent branches of trees, some of them of existing species, has demonstrated the solidity of the reasonings founded on its general structure and aspect. The pseudo-traditions, however, represent it in every instance as a carnivorous tyrant, that, had it not been itself destroyed, would have destroyed all the other animals its contemporaries. It is said by the red men of Virginia, “that a troop of these tremendous quadrupeds made fearful havoc for some time among the deer, the buffaloes, and all the other animals created for the use of the Indians, and spread desolation far and wide. At last ‘the Mighty Man above’ seized his thunder and killed them all, with the exception of the largest of the males, who presenting his head to the thunderbolts, shook them off as they fell; but, being wounded in the side, he betook himself to flight towards the great lakes, where he still resides at the present day.”
Let me here remind you in the passing, that that antiquity of type which characterizes the recent productions of North America is one of many wonders,—not absolutely geological in themselves, but which, save for the revelations of geology, would have forever remained unnoted and unknown,—which have been pressed, during the last half century, on the notice of naturalists. “It is a circumstance quite extraordinary and unexpected,” says Agassiz, in his profoundly interesting work on Lake Superior, “that the fossil plants of the Tertiary beds of Oeningen resemble more closely the trees and shrubs which grow at present in the eastern parts of North America, than those of any other parts of the world; thus allowing us to express correctly the difference between the opposite coasts of Europe and America, by saying that the present eastern American flora, and, I may add, the fauna also, have a more ancient character than those of Europe. The plants, especially the trees and shrubs, growing in our days in the United States, are, as it were, old-fashioned; and the characteristic genera Lagomys, Chelydra, and the large Salamanders with permanent gills, that remind us of the fossils of Oeningen, are at least equally so;—they bear the marks of former ages.” How strange a fact! Not only are we accustomed to speak of the eastern continents as the Old World, in contradistinction to the great continent of the west, but to speak also of the world before the Flood as the Old World, in contradistinction to the post-diluvian world which succeeded it. And yet equally, if we receive the term in either of its acceptations, is America an older world still,—an older world than that of the eastern continents,—an older world, in the fashion and type of its productions, than the world before the Flood. And when the immigrant settler takes axe amid the deep backwoods, to lay open for the first time what he deems a new country, the great trees that fall before him,—the brushwood that he lops away with a sweep of his tool,—the unfamiliar herbs which he tramples under foot,—the lazy fish-like reptile that scarce stirs out of his path as he descends to the neighboring creek to drink,—the fierce alligator-like tortoise, with the large limbs and small carpace, that he sees watching among the reeds for fish and frogs, just as he reaches the water,—and the little hare-like rodent, without a tail, that he startles by the way,—all attest, by the antiqueness of the mould in which they are cast, how old a country the seemingly new one really is,—a country vastly older, in type at least, than that of the antediluvians and the patriarchs, and only to be compared with that which flourished on the eastern side of the Atlantic long ere the appearance of man, and the remains of whose perished productions we find locked up in the loess of the Rhine, or amid the lignites of Nassau. America is emphatically the Old World. If we accept, however, as sound the ingenious logic by which Colton labors to show, in not inelegant verse, that the Moderns are the true Ancients, we may continue to term it the New World still.
“We that on these late days are thrown
Must be the oldest Ancients known;
The earliest Modern earth hath seen
Was Adam in his apron green.
He lived when young Creation pealed
Her morning hymn o’er flood and field,
Till all her infant offspring came
To that great christening for a name.
And he that would the Ancients know,
Must forward come, not backward go:
The learned lumber of the shelves
Shows nothing older than ourselves.
But who in older times than we
Shall live?—That infant on the knee,—
See sights to us were never shown,
And secrets known to us unknown.”
The group of mammals which, in Europe, at least, immediately preceded the human period seems to have been everywhere a remarkable one; and nowhere was it more so than in the British islands. Our present mammaliferous fauna is rather poor; but the contents of the later deposits show that we must regard it as but a mere fragment of a very noble one. Associated with species that still exist in the less cultivated parts of the country, such as the badger, the fox, the wild cat, the roe and the red deer, we find the remains of great animals, whose congeners must now be sought for in the intertropical regions. Britain, during the times of the boulder clay, and for ages previous, had its native elephant, its two species of rhinoceros, its hippopotamus, its hyæna, its tiger, its three species of bears, its two species of beavers, its great elk, and its gigantic deer. Forms now found widely apart, and in very different climates, meet within the British area. During at least the earlier times of the group, the temperature of our island seems to have been very much what it is now. As I have already had occasion to remark, the British oak flourished on its plains and lower slopes, and the birch and Scotch fir on its hills. And yet under these familiar trees the lagomys or tailless hare, a form now mainly restricted to Siberia and the wilds of Northern America, and the reindeer, an animal whose proper habitat at the present time is Lapland, were associated with forms that are now only to be found between the tropics, such as that of the hippopotamus and rhinoceros. These last, however, unequivocally of extinct species, seem to have been adapted to live in a temperate climate; and we know from the famous Siberian specimen, that the British elephant, with its covering of long hair and closely-felted wool, was fitted to sustain the rigors of a very severe one. It is surely a strange fact, but not less true than strange, that since hill and dale assumed in Britain their present configuration, and the oak and birch flourished in its woods, there were caves in England haunted for ages by families of hyænas,—that they dragged into their dens with the carcasses of long extinct animals those of the still familiar denizens of our hill-sides, and feasted, now on the lagomys, and now on the common hare,—that they now fastened on the beaver or the reindeer, and now upon the roebuck or the goat. In one of these caves, such of the bones as projected from the stiff soil have been actually worn smooth in a narrow passage where the hyænas used to come in contact with them in passing out and in; and for several feet in depth the floor beneath is composed almost exclusively of gnawed fragments, that still exhibit the deeply indented marks of formidable teeth. In the famous Kirkdale cave alone, parts of the skeletons of from two to three hundred hyænas have been detected, mixed with portions of the osseous framework of the cave-tiger, the cave-bear, the ox, the deer, the mammoth, and the rhinoceros. That cave must have been a den of wild creatures for many ages ere the times of the boulder clay, during which period it was shut up from all access to the light and air by a drift deposit, and lay covered over until again laid open by some workmen little more than thirty years ago. Not only were many of the wild animals of the country which still exist contemporary for a time with its extinct bears, tigers, and elephants, but it seems at least highly probable that several of our domesticated breeds derived their origin from progenitors whose remains we find entombed in the bone-caves and other deposits of the same age; though of course the changes effected by domestication in almost all the tame animals renders the question of their identity with the indigenous breeds somewhat obscure. Cuvier was, however, unable to detect any difference between the skeleton of a fossil horse, contemporary with the elephant, and that of our domestic breed: a fossil goat of the same age cannot be distinguished from the domesticated animal; and one of our two fossil oxen (Bos longifrons) does not differ more from some of the existing breeds than these have, in the course of time, been made, chiefly by artificial means, to differ among themselves. But of one of our domestic tribes no trace has yet been found in the rocks: like the cod family among fishes, or the Rosaceæ among plants, it seems to have preceded man by but a very brief period. And certainly, if created specially for his use, though the pride of the herald might prevent him from selecting it as in aught typical of the human race, it would yet not be easy to instance a family of animals that has ministered more extensively to his necessities. I refer to the sheep,—that soft and harmless creature, that clothes civilized man everywhere in the colder latitudes with its fleece,—that feeds him with its flesh,—that gives its bowels to be spun into the catgut with which he refits his musical instruments,—whose horns he has learned to fashion into a thousand useful trinkets,—and whose skin, converted into parchment, served to convey to later times the thinking of the first full blow of the human intellect across the dreary gulf of the middle ages.
At length the human period begins. A creature appears upon the scene unlike all that had preceded him, and whose nature it equally is to look back upon the events of the past,—among other matters, on that succession of beings upon the planet which he inhabits, with which we are this evening attempting to deal,—and to anticipate at least one succession more, in that still future state in which he himself is again to appear, in happier circumstances than now, and in a worthier character. We possess another history of the primeval age and subsequent chronology of the human family than that which we find inscribed in the rocks. And it is well that we do so. From various causes, the geologic evidence regarding the period of man’s first appearance on earth is singularly obscure. That custom of “burying his dead out of his sight,” which obtained, we know, in the patriarchal times, and was probably in use ever since man came first under the law of death, has had the effect of mingling his remains with those of creatures that were extinct for ages ere he began to be. The cavern, once a haunt of carnivorous animals, that in the first simple ages of his history had furnished him with a shelter when living, became his burying-place when dead; and thus his bones, and his first rude attempts in pottery and weapon-making, have been found associated with the remains of the cave-hyæna and cave-tiger, with the teeth of the ancient hippopotamus, and the tusks of the primeval elephant. The evidence on the point, too,—from the great paucity of human remains of a comparatively remote period, and from the circumstance that they are rarely seen by geologists in the stratum in which they occur,—is usually very imperfect in its details. Further, it is an evidence obnoxious to suspicion, from the fact that a keen controversy has arisen on the subject of man’s antiquity, that such fragments of man himself or of his works as manifest great age have been pressed to serve as weapons in the fray,—that, occurring always in superficial and local deposits, their true era may be greatly antedated, under the influence of prejudice, by men who have no design wilfully to deceive,—and that while, respecting the older formations, with their abundant organisms, the conclusions of any one geologist may be tested by all the others, the geologist who once in a lifetime picks up in a stratified sand or clay a stone arrow-head or a human bone, finds that the data on which he founds his conclusions may be received or rejected by his contemporaries, but not re-examined. It may be safely stated, however, that that ancient record in which man is represented as the lastborn of creation, is opposed by no geologic fact; and that if, according to Chalmers, “the Mosaic writings do not fix the antiquity of the globe,” they at least do fix—making allowance, of course, for the varying estimates of the chronologer—“the antiquity of the human species.” The great column of being, with its base set in the sea, and inscribed, like some old triumphal pillar, with many a strange form,—at once hieroglyphic and figure,—bears, as the ornately sculptured capital, which imparts beauty and finish to the whole, reasoning, responsible man. There is surely a very wonderful harmony manifested in the proportions of that nice sequence in which the invertebrates—the fishes, the reptiles, the birds, the marsupials, the placental mammals, and, last of all, man himself—are so exquisitely arranged. It reminds us of the fine figure employed by Dryden in his first Ode for St. Cecilia’s Day,—a figure which, viewed in the light cast on it by the modern science of Palæontology, stands out in bolder relief than that in which it could have appeared to the poet himself:—
“From harmony, from heavenly harmony,
This universal frame began;
From harmony to harmony,
Through all the compass of the notes it ran,
The diapason closing full in man.”
In the limits to which I have restricted myself, I have been able to do little more than simply to chronicle the successive eras in which the various classes and divisions of the organic kingdom, vegetable and animal, make their appearance in creation. I have produced merely a brief record of the various births, in their order, of that great family whose father is God. And in pursuing such a plan, much, of necessity, must have been omitted. I ought perhaps to have told you, that very rarely, if ever, do the master forms of a period constitute the prevailing or typical organisms of its deposits. Of the three great divisions of which the geologic scale consists,—Palæozoic, Secondary, and Tertiary,—the first, or ichthyic period, is marked chiefly, not by its great fishes, but by the peculiar character of its brachipodous and cephalopodous mollusca, and in its earlier stages by its three-lobed crustaceæ; the second or reptilian period was emphatically the period of the ammonite and belemnite; while the third and last, or mammalian period, was that of gastropodous and conchiferous molluscs, impressed, generically at least, by all the features of the group which still exists in our seas. Save in a few local deposits, fishes do not form the prevailing organisms in the formations of the age of fishes; nor reptiles in the formations of the age of reptiles; nor yet mammals in the formations of the age of mammals. Nay, it is not improbable that the recent or human period may be marked most prominently in the future, when it comes to exist simply as a geologic system, by a still humbler organism than most of these molluscs. On almost all rocky shores a line of pale gray may be seen at low water, running for mile after mile along the belt that has been laid bare at the bases of the cliffs by the fall of the tide. It owes its pale color to millions of millions of a small balanus (B. balanoides), produced in such amazing abundance in the littoral zone as to cover with a rough crust every minute portion of rock and every sedentary shell. Other species of the same genus (B. crenatus and B. porcatus) occupy the depths of the sea beyond; and their remains, washed ashore by the waves, and mingled with those of the littoral species, form often great accumulations of shell sand. I have seen among the Hebrides a shell sand accumulated along the beach to the depth of many feet, of which fully two thirds was composed of the valves and compartments of balanidæ; and a similar sand on the east coast of Scotland, a little to the south of St. Andrews, formed in still larger proportions of the fragments of a single species,—Balanus crenatus. Now, this genus, so amazingly abundant at the present time in every existing sea, and whose accumulated remains bid fair to exist as great limestone rocks in the future, had no existence in the Palæozoic or Secondary ages. It first appears in the times of the earlier Tertiary, in, however, only a single species; and, becoming gradually of more and more importance as a group, it receives its fullest numerical development in the present time. And thus the remains of a sub-class of animals, low in their standing among the articulata, may form one of the most prominent Palæontological features of the human period. But enough for the present of circumstance and detail.
(Red Crag.)
Such, so far as the geologist has yet been able to read the records of his science, has been the course of creation, from the first beginnings of vitality upon our planet, until the appearance of man. And very wonderful, surely, has that course been! How strange a procession! Never yet on Egyptian obelisk or Assyrian frieze,—where long lines of figures seem stalking across the granite, each charged with symbol and mystery,—have our Layards or Rawlinsons seen aught so extraordinary as that long procession of being which, starting out of the blank depths of the bygone eternity, is still defiling across the stage, and of which we ourselves form some of the passing figures. Who shall declare the profound meanings with which these geologic hieroglyphics are charged, or indicate the ultimate goal at which the long procession is destined to arrive?
The readings already given, the conclusions already deduced, are as various as the hopes and fears, the habits of thought, and the cast of intellect, of the several interpreters who have set themselves,—some, alas! with but little preparation and very imperfect knowledge,—to declare in their order the details of this marvellous, dream-like vision, and, with the dream, “the interpretation thereof.” One class of interpreters may well remind us of the dim-eyed old man,—the genius of unbelief so poetically described by Coleridge,—who, sitting in his cold and dreary cave, “talked much and vehemently concerning an infinite series of causes and effects, which he explained to be a string of blind men, the last of whom caught hold of the skirt of the one before him, he of the next, and so on, till they were all out of sight, and that they all walked infallibly straight, without making one false step, though all were alike blind.” With these must I class those assertors of the development hypothesis who can see in the upward progress of being only the operations of an incomprehending and incomprehensible law, through which, in the course of unreckoned ages, the lower tribes and families have risen into the higher, and inferior into superior natures, and in virtue of which, in short, the animal creation has grown, in at least its nobler specimens, altogether unwittingly, without thought or care on its own part, and without intelligence on the part of the operating law, from irrational to rational, and risen in the scale from the mere promptings of instinct to the highest exercise of reason,—from apes and baboons to Bacons and Newtons. The blind lead the blind;—the unseeing law operates on the unperceiving creatures; and they go, not together into the ditch, but direct onwards, straight as an arrow, and higher and higher at every step.
Another class look with profound melancholy on that great city of the dead,—the burial-place of all that ever lived in the past,—which occupies with its ever-extending pavements of gravestones, and its ever-lengthening streets of tombs and sepulchres, every region opened up by the geologist. They see the onward procession of being as if but tipped with life, and nought but inanimate carcasses all behind,—dead individuals, dead species, dead genera, dead creations,—a universe of death; and ask whether the same annihilation which overtook in turn all the races of all the past, shall not one day overtake our own race also, and a time come when men and their works shall have no existence save as stone-pervaded fossils locked up in the rock forever? Nowhere do we find the doubts and fears of this class more admirably portrayed than in the works of perhaps the most thoughtful and suggestive of living poets:—
“Are God and Nature then at strife,
That Nature lends such evil dreams,
So careful of the type she seems,
So careless of the single life?
‘So careful of the type!’ but no,
From scarped cliff and quarried stone,
She cries, ‘A thousand types are gone;
I care for nothing; all shall go:
Thou makest thine appeal to me;
I bring to life, I bring to death;
The spirit does but mean the breath.
I know no more.’ And he,—shall he,
Man, her last work, who seemed so fair,
Such splendid purpose in his eyes,
Who rolled the psalm to wintry skies
And built him fanes of fruitless prayer,
Who trusted God was love indeed,
And love creation’s final law,
Though Nature, red in tooth and claw,
With ravine shrieked against his creed,—
Who loved, who suffered countless ills,
Who battled for the true, the just,—
Be blown about the desert dust,
Or sealed within the iron hills?
No more!—a monster then, a dream,
A discord. Dragons of the prime,
That tore each other in their slime,
Were mellow music matched with him.
O, life, as futile then as frail,—
O for thy voice to soothe and bless!
What hope of answer or redress,
Behind the vail, behind the vail!”
The sagacity of the poet here,—that strange sagacity which seems so nearly akin to the prophetic spirit,—suggests in this noble passage the true reading of the enigma. The appearance of man upon the scene of being constitutes a new era in creation; the operations of a new instinct come into play,—that instinct which anticipates a life after the grave, and reposes in implicit faith upon a God alike just and good, who is the pledged “rewarder of all who diligently seek Him.” And in looking along the long line of being,—ever rising in the scale from higher to yet higher manifestations, or abroad on the lower animals, whom instinct never deceives,—can we hold that man, immeasurably higher in his place, and infinitely higher in his hopes and aspirations, than all that ever went before him, should be, notwithstanding, the one grand error in creation,—the one painful worker, in the midst of present trouble, for a state into which he is never to enter,—the befooled expectant of a happy future, which he is never to see? Assuredly no. He who keeps faith with all his humbler creatures,—who gives to even the bee and the dormouse the winter for which they prepare,—will to a certainty not break faith with man,—with man, alike the deputed lord of the present creation, and the chosen heir of all the future. We have been looking abroad on the old geologic burying-grounds, and deciphering the strange inscriptions on their tombs; but there are other burying-grounds, and other tombs,—solitary churchyards among the hills, where the dust of the martyrs lies, and tombs that rise over the ashes of the wise and good; nor are there awanting, on even the monuments of the perished races, frequent hieroglyphics, and symbols of high meaning, which darkly intimate to us, that while their burial-yards contain but the debris of the past, we are to regard the others as charged with the sown seed of the future.