not quite confined to that region, are more plentiful there than elsewhere, and are successors of fossil races also found almost exclusively in that country. Thus the fossil Megatherium has been compared with the Sloth, the Glyptodon with the Armadillo; nor does the enormous bulk of the fossils hinder the reception of them into the same natural families. The same lands then have been in successive periods peopled by analogous races, and thus we have manifested 'a wonderful relationship on the same continent between the dead and the living1.' Still this succession of similar forms is limited to Cænozoic ages. One other example must suffice. The marsupial peculiarity of Australian Mammalia is not of modern date; the Australian caves contain evidence of the same character in the races whose remains are there preserved. The peculiarity indeed is of far earlier origin, for it occurs in the Eocene deposits of the basin of Paris, in the Lacustrine deposits over the upper Oolite in Purbeck, in the lagoon of the great Oolite at Stonesfield, and probably in the Trias of Würtemberg. In respect of the Stonesfield fossils, this is not the only evidence presented by that curious deposit of similarity of Mesozoic life in the north, and Cænozoic life in the antipodal region of the south. It extends to other groups, both of the land and sea, and almost justifies the notion of some affinity even in the systems of life. For just as at Stonesfield, so in Australia, small insectivorous marsupial mammals are associated with Cycadaceous Plants and Ferns; as now in the seas surrounding Australia, Terebratula and Rhynchonella, Trigonia and Cucullæa, consort with Turtles and the Cestraciont Sharks, near reefs of Coral, and rivers tenanted by Gavialian Crocodiles, so at Stonesfield in the older time, similar animals in similar combination. 1 Darwin. This author does not suppose the living Edentata of the same region to be the dwarfed descendants of these monstrous beasts, but speaks of some others, their contemporaries in time and companions in the same caverns, which may be regarded as the progenitors of the living species. What does this teach us? Are we looking upon two partially similar but really separate creations suited to partially similar conditions in very different periods of time? Or is the life-system of the modern Australian land and sea truly derived in some of its components by descent with modification from the older periods of the world, and preserved to this our day, notwithstanding displacement over half the circumference of the globe, and all the vicissitudes of an immensity of time? Whoever has the courage to adopt the latter view, must accept with it the obvious inference that in all the countless ages which have rolled away since the branches of Zamia were blown into the lagoon of Stonesfield, the amount of organic change has been small in each group of plants and animals ; that a similar amount of change affected the unlike inhabitants of land and sea; that Mollusca and Sharks, and Turtles and Crocodiles, have all been modified by differences of a small description in passing from Oolitic to modern times, while not only hosts of Ammonites and Belemnites have perished in the experiment, but many new forms, as Oliva, Mitra, Triton, Struthiolaria, unknown in the earlier period, have come into view in the latter! But let it be adopted. What follows? These small differences then, accomplished in all that prodigious range of elapsed time, under all that variety of physical changes and removals, these are all the mutations which have been possible under the constant tendency of hereditary descent to perpetuate similar forms with modification. One of these genera, that of Trigonia, is known to be in the fossil state rich in species; supposing them to have all come from one original typical form, the differences which they shew in strata of the same system, deposited within the same grand period, and under much similarity of conditions, argues a facility in giving variations; let this operation be supposed to be continued in the interval between the epoch of Stonesfield and that of Australia, and the effects summed by natural selection, the result is the modern Trigonia, scarcely differing more in appearance from the fossil species than they differ one from another. But if not so derived, by continual descent, but sprung from separate contemporaneous branches of one stem of life, arriving at a given standard of excellence at such enormously different epochs, how should it happen that Plants and Quadrupeds on land, Sharks and Mollusks in the sea, should in each of these two cases pass with equal advance along the streams of change, moving in one case so fast, in the other so slow? But if the branches sprang at different times and led to these similar results, would this double origin in time, for several similar forms, in similar associations, fit with the hypothesis of continual development? THEORIES AND OPINIONS. FORMED STONES. THREE centuries have glided by since Bernard Palissy, the philosophic potter of Xaintonge, revived the ancient opinion of Herodotus1 and Pythagoras", and wrote the simple words, 'Je t'ay monstré plusieurs coquilles reduites en pierre.' France may well be proud of him, for he was among the first who ever uttered in modern Europe sensible remarks on the subject of Palæontology, and they fell on incredulous ears. Two centuries only remove us from Agostino Scilla, the worthy Italian painter, who strove to dissipate false speculations regarding petrified marine exuviæ, by excellent drawings of recent and fossil teeth, Echinida and shells, from the Tertiary Strata of Messina and Malta. What these false speculations were, is too well known to the readers of our earliest English authors, Plot, Llwydd, Lister, Ray, and Wood 1 Euterpe, 12. 2 Ovid, Metam. 3 The first of Palissy's Essays is dated 1557; the complete work 1580; Gessner's work, De omni rerum fossilium genere, &c., was printed at Zurich in 1565. 4 La vana speculazione disingannata. Earliest Edition, 1670. |