equally peculiar. Hence it is plain 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 character 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 permanent in the oldest fishes was gradually reduced, till in more recent periods, and in the present creation, the fishes lost all their herpetological relationship, and were at last endowed with characters which contrast as much with those of Reptiles as they agreed closely in the beginning." In a few existing forms, (Lepidosteus of America, and Polypterus of the Nile,) and in all primeval fishes, the pelvis and posterior limbs retained their position in connexion with the point of junction of trunk and tail, a character indicating superiority of type. This does not apply to the fishes of subsequent epochs, for, from the period of the chalk formation down to our own day, a large proportion of them have the ventral or hind fins rcmoved from the typical position and placed far forwards, near the head. Such position of posterior limbs in the very dawn of vertebrate creation, indicates an arrangement which was largely to prevail in the vertebrata of subsequent epochs. The Telerpeton of the Elgin sandstone ushered in the dawn of reptilian life; it is the earliest of its class yet known to us. Fitted for a sphere of existence different from that proper to fishes, it presents to our view a new modification of the vertebrate plan. Its well developed limbs point to a character which was to come forth more prominently in succeeding periods. * Natural History of Lake Superior. In 1726, Scheuchzer detected, in the comparatively recent rock of Eningen, a fossil which he set down as human, styling it "homo diluvii testis," (man a witness of the flood.) This opinion did not stand the test of comparative anatomy, and the supposed human relic turned out to be that of a large salamander. The time had not yet arrived for the advent of man; long ages had yet to roll on before the consummation of the vertebrate type; the preparations for man's appearance were not yet completed. Nevertheless, in this fossil of Scheuchzer's, there was a prefiguration of the more perfect type which man's bony framework presents. In 1847, Professor Plieninger of Stutgardt found two fossil molar teeth, which must have belonged to a warmblooded quadruped; they were disinterred from a bonebed in Wurtemburg, lying between the Lias and Keuper formations. The original owner of these interesting relics is supposed to have been an insect-feeder. A well-marked tooth, pronounced on the highest authority, to have been that of a warm-blooded quadruped, implies adaptations of the vertebrate archetype of a far higher character than any yet indicated in previous geological records. Such a relic indicates associations of structure which are found in man himself; and at this point in the earth's history, we have the herald of the great mammalian class at the head of which man is placed-the first in nature, though the last in time. Certain bipedal footsteps in the new red sandstone of Connecticut, are recognized as those of birds. Man, the true biped, was to appear in a subsequent and still distant epoch. But such early impressions and remains are not with*It is agreed on all hands that the origin of the human species is of comparatively modern date. All fossil human remains, those of Guadaloupe, for example, are within the historical epoch. out their instruction; we may recognise in all these preexistent beings the same type of skeleton, the beau ideal of which was to come forward in the time appointed, after the lapse of long ages. Fishes, reptiles, birds, and mammals, predecessors of man, presented in their frames anticipations of more perfect structures which characterize him. They had arrangements to protect the eye and the organ of hearing, a bony vault to contain the brain, and limbs for various functions necessary to their wellbeing. The Supreme could foresee that which was to come, and which He had pre-ordained; the revelations of geology enables us to take a retrospective view. But they do more; they afford us the means of exercising a reflex faculty; we can examine the first figure in the vertebrate series, and from that point look down the long vistas which are opened, to the period when man appears as the final and foreseen product of the one mighty plan-the last in time, but the first in the contemplation of Him. who called them all into being. Precedent vertebrata shadowed forth certain peculiarities of frame and of psychical powers, which have their full, and evidently intended, significance brought out and manifested only in When he appears on the scene which had been so long prepared, and, as it were, waiting for him, the consummation of the earthly type comes out ;-in a goodly frame, with gait erect; in eyes to contemplate, and mental faculties to appreciate, the beauty of the objects around him; in limbs to bear that frame upright, and carry it on in the fulfillment of its high sphere of duties and in hands to minister to the wants of the individual and of his fellows. Doubtless the structure of his body binds him to the earth's surface, but he has mental powers which enables him to soar from earth to heaven, man. ; to penetrate far into the regions of space, and throw back a reflective glance upon the remotest points of time. In the exercise of these mental faculties, it is expected of him that he should contemplate with wonder and adoration the wondrous scene spread out before him; and in the survey of the past he can discover that the earliest fishes of the palæozoic age pointed onwards to a higher realization of the vertebrate plan; that the plan has never in any succeeding age been departed from; that it was at last perfected in his own wonderful frame; and that all this had been from eternity in the counsel of Him who worketh in the whole from the beginning unto the end. We are happy to be able to adduce, in favour of this general view, the testimony of the two greatest living comparative anatomists. "It is evident," says Agassiz,* "that there is a manifest progress in the succession of beings on the surface of the earth. This progress consists in an increasing similarity to the living fauna, and among the vertebrata, especially in their increasing resemblance to man. But this connection is not the consequence of a direct lineage between the faunas of different ages. There is nothing like parental descent connecting them. The fishes of the Palæozoic age are in no respect the ancestors of the reptiles of the secondary age, nor does man descend from the mammals which preceded him in the tertiary age. The link by which they are connected is of a higher and immaterial nature; and their connexion is to be sought in the view of the Creator Himself, whose aim in forming the earth, in allowing it to undergo the successive changes which geology has pointed out, and in creating successively all the different types of animals which have passed away, was * Agassiz and Gould's Comparative Physiology, p. 417. to introduce man upon its surface. Man is the end towards which all the animal creation has tended from the first appearance of the first Palæozoic fishes." The language of Owen is equally explicit. "The recognition of an ideal exemplar in the vertebrated animals proves that the knowledge of such a being as man must have existed before man appeared; for the Divine Mind which planned the archetype also foreknew all its modifications. The archetype idea was manifested in the flesh long prior to the existence of those animal species that actually exemplify it. To what natural laws or secondary causes the orderly succession and progression of such organic phenomena may have been committed, we are as yet ignorant. But if, without derogation of the Divine power, we may conceive of the existence of such ministers, and personify them by the term 'Nature,' we learn from the past history of our globe that she has advanced with slow and stately steps, guided by the archetypal light amidst the wreck of worlds, from the first embodiment of the vertebrate idea under its old ichthyic vestment, until it became arrayed in the glorious garb of the human form." SECT. II.-ADAPTATIONS OF FOSSIL ORGANISMS TO THEIR FUNCTIONS. Plants. The stem of the extinct plant (now converted into stone) must have been as well fitted to sustain itself erect, to receive and convey the fluids taken in by the roots, and to support leaves for the elaboration of these fluids, as the axis of any of our living trees. If we meet with but the impression of a leaf, we cannot avoid drawing the conclusion that the original, now lost to us, must * On Limbs, p. 86. |