nosperms; and Sir Charles admits both the fact and its remarkable character, viz., that none of the exogens of Lindley or dicotyledonous angiosperms of Brongniart, which comprise fourfifths of the living flora of the globe, have yet been discovered in the coal measures. It must be remembered, too, when the value. of negative evidence is called in question, that the whole of Europe does not produce more than 50 species of ferns-only one-fifth of the number that have left their remains in our coal strata; and accordingly M. Brongniart has called the flora of the carboniferous and Permian strata the age of Acrogens.'

In the strata from the triassic to the Purbeck inclusive, plants of the family of Zamia and Cycas, together with coniferæ, predominated in Europe far more than anywhere now on the globe in corresponding latitudes, and this fauna Brongniart calls the 'age of Gymnosperms.'

Now, we presume, it will be admitted that Cryptogamia, Phanogamia, Gymnosperms, and Dicotyledonous Angiosperms constitute a succession and a progressive one; this is the order in which our present collection of facts compels us to arrange the records of the ancient evidences of vegetable life; and no suggestion of the possibility of contradictory facts, as yet undiscovered, can avail to subvert that order, or ought to affect the conclusions legitimately deducible from it. It is true that there is no very great difference in the perfection or complexity of the organs, of a monocotyledonous and a dicotyledonous plant, but it is that very similarity in their grade of structure which diminishes the force of any argument drawn from vegetable fossils against the ideas of progression which have been derived from a comparison of the fossil remains of the animal kingdom. If there be some analogy in the succession of forms of the vegetable kingdom, showing a progressively nearer approach to those that now prevail, with the more striking progress towards actual forms in the successive tribes of the animal kingdom, it is as much as can be expected to be deduced from vegetable palæontology in reference to the main question at issue between the Progressionist and Uniformitarian. The Address proceeds:

'Fifthly, in regard to the animal kingdom, the lowest Silurian strata contain highly developed representatives of the three great divisions of radiata, articulata, and mollusca, showing that the marine invertebrate animals were as perfect then as in the existing seas. They also comprise some indications of fish, the scarcity of which in a fossil state, as well as the absence of cetacea, does not appear inexplicable in the present imperfect state of our investigations, when we consider the corresponding rarity and sometimes the absence of the like remains observed in dredging the beds of existing seas.'

'Sixthly,

Sixthly, the upper Silurian group contains amongst its fossil fish cestraciont sharks, than which no ichthyic type is more elevated.'

It is very true that representatives of all the four leading divisions of the animal kingdom are met with in the earliest sedimentary deposits containing any records of organised beingsin other words, in the lowest Silurian strata. Not only do species of Radiata, Articulata, and Mollusca here occur, but remains of Vertebrata have been found: these, however, are confined to indications of a cold-blooded reptile and to remains of fishes-and amongst the latter no trace of a well-ossified vertebral column appears. Nay, even those piscine remains that have been discovered in the upper Silurian group show a retention of the same embryonic state of the skeleton; although, by the analogy of the recent cestracion, we may infer that a well-developed fish's brain and reproductive system were combined with the cartilaginous backbone. But Sir Charles Lyell makes a large demand upon our faith in possible contingencies when, referring to the rarity, and sometimes the absence, of cetaceous remains observed in dredging the beds of existing seas, he deems that the causes of such scarcity or absence may explain the non-discovery hitherto of cetacea in the lowest Silurian strata.-If, notwithstanding the vast numbers of fossil fishes that have been discovered in Silurian and Devonian beds, not one evidence of an ossified body of a vertebra has occurred, whilst almost all the species have shown the dermal skeleton developed in excess, the probability of warm-blooded cetacea, with a smooth vascular skin and well-ossified internal vertebral column having co-existed with such crustaceous-like fishes, will not appear very great.

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Seventhly, in the carboniferous fauna there have been recently discovered several skeletons of reptiles of by no means a low or simple organization, and in the Permian there are saurians of as high a grade as any now existing, while the absence of terrestrial mammalia in the palæozoic rocks generally may admit of the same explanation as our ignorance of most of the insects and all the pulmoniferous mollusca, as well as of Helices and other land shells of the same era.'—Ib.

With regard to the carboniferous epoch, the President of the Geological Society, in the Proposition above cited, reminds the members that there have been recently discovered several skeletons of reptiles of by no means a low or simple organization.' But no reptile has an organization that can properly be called simple or low-no fish even; for the vertebrated type is the highest of all. The question is whether the carboniferous fauna has yielded any evidence of a reptile which presents a high and complex organization compared to the rest of its class.

The reptiles to which Sir Charles refers in his Address are

those,

those, probably, that are indicated by foot-prints in the coal strata of Greensburgh, Pennsylvania, and which he had an opportunity of examining in 1846. He says (Manual, p. 337), ‘I was at once convinced of their genuineness;'-but we confess that we should have valued the conclusion more highly if it had been more deliberately arrived at. We, however, by no means doubt the accuracy of the inferences that have been drawn as to the general character of the animal that left the foot-prints in question. These prints were first observed standing out in relief from the lower surface of slabs of sandstone, resting on thin layers of fine unctuous clay. Casts of cracks occasioned by the shrinking and drying of the clay accompany, and sometimes traverse, the footsteps, producing distortion in them; for the clay must have been soft when the animal walked over it and left the impressions, whereas, when it afterwards dried up and shrank, it would be too hard to receive such indentations. The foot-prints bear the greatest resemblance to those which have been discovered in the new red sandstones of Europe, and have been referred to an animal called Chirotherium; but the fore foot of the American Chirothere was less small in proportion to the hind foot, and it shows but four toes. The European Chirothere was at first conjectured, by Dr. Kaup, to have been a mammiferous animal allied to the opossum, but geologists have since adopted the conclusions of Professor Owen, that it was a reptile, having, like the Labyrinthodons, the most essential affinities to the Batrachian order.

Something better than footprints were discovered about the same period in the coal formations of Münster-Appel in Rhenish Bavaria―viz. the skull, vertebral column, and some bones of the extremities, of an animal which was referred by the able palæontologist of Frankfürt, M. Herman von Meyer, to the class of reptiles, under the name of Apateon pedestris. In 1847 Prof. von Dechen found in the coal-field of Saarbrück, at the village of Lebach, between Strasburg and Treves, the skeletons of three species of reptiles, which were described by Goldfuss under the generic name of Archegosaurus. These reptiles are regarded by both Von Meyer and Owen as being most nearly allied to the perennibranchiate Batrachia, e. g. the Proteus anguinus-only that they combined with their short and simple ribs a better development of the dermal skeleton, in that respect showing their analogy with most of the fishes of the same and antecedent periods.

Had mammalia existed in the same number and variety in the ancient forests that have contributed to the coal strata, as in the actual woods and swamps of the warmer parts of the globe-had armadillos and anteaters been then created to feed on the insects, sloths on the leaves, and monkeys on the fruits of the coal plants,

as

as they now do in the Brazilian forests, where the mammals preponderate over reptiles, we might have expected the first evidence of an air-breathing vertebrate animal discovered in the coal fields to have been mammalian. The osseous tissue of the skeletons of this class is a substance better adapted for preservation in a fossil state than the soft coverings of insects; and the diminutive size of these perishable creatures must be taken into the account, in their comparison with the higher vertebrate classes, with reference to the probabilities of the discovery of their fossilized remains. When, therefore, we find the eloquent President affirming (ibid.) that the absence of land mammalia in the palæozoic rocks generally may admit of the same explanation as our ignorance of most of the insects and other terrestrial invertebrata of the same era, we can only attribute the oversight of the circumstances more favourable to the discovery of mammals to the influence of those uniformitarian views that have chiefly guided his labours in this field of science.

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Eighthly, the fish and reptiles of the secondary rocks are as fully developed in their organization as those now living. The birds are represented by numerous foot-prints and coprolites in the Trias of New England, and by a few bones, not yet generically determined, from Stonesfield and the English Wealden.'—Ib. 22.

It is no argument against the views that naturally arise out of the summary of the facts of Palæontology as they are now known, to urge that the fish and reptiles of the secondary rocks are as fully developed in their organization as those now living.' A fish must have the grade of organization of its class as such-and so of a reptile. The question is, whether the vertebrata of those classes bore the same proportion to birds and mammals as they now do?-whether the estuary and fresh-water formations of the secondary periods manifest as large a proportion of the fossil remains of warm-blooded animals, as those formations of the present period might be expected to do, or even as the same formations of the tertiary periods actually have done?

Before entering upon this question we will return to the eighth proposition which the President expects to establish in opposition to the theory of successive development. Our readers will remark that he cautiously abstains from the use of the word 'progressive.' Throughout his Address he tries to show that the doctrine of successive development is not palæontologically true.' We cannot suppose that in substituting successive' for 'progressive' he would ignore the main conclusion of Palæontology. He nowhere at least extends his argument er ignoto to the explanation of the non-discovery of forms, now only known as peculiar to the formations of one period, in those of an antecedent or of a later

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period.

period. We take for granted, therefore, that he does not wish to be understood as endeavouring to oppose the generally admitted inference, based on the actual state of palæontology, that the order of things in past time so far differed from that of the present as to require new species of animals to be successively created, and adapted, as we must suppose, to as many successively differing conditions of the surface of our planet.

Every fish and every reptile was doubtless as perfectly adapted to the circumstances under which it lived at the remotest of the Geological periods, as any fish or reptile at the present day: in that respect it was 'as fully developed.' Palæontology, however, has made us acquainted with different races of fishes in different formations, to which those races respectively are peculiar, and of which they are consequently characteristic; and as those formations succeeded each other in point of time, so we infer that the different races of fishes were successively developed. But what Sir Charles Lyell appears to be contending for is, that the forms of animal life that succeeded each other did not differ in the grade of their organization; man, of course, always excepted.

No doubt every fish is alike perfect in relation to its sphere of existence; but a gradation of complexity of organization is traceable throughout the class, as we now know it, and the lancelet and lamprey are, in this comparison, pronounced by naturalists to be inferior to, or less fully developed than, the tunny or the shark. There is, however, but a short range of gradation within the limits of this class as compared with that which extends from the fish to the mammal, or from the invertebrate to the vertebrate series ; and in the class of fishes it is seen that when a species overpasses another in certain organs, as, e. g., in the brain or the parts of generation, the advance is usually counterbalanced by a less full development of some other system, as, e. g., the respiratory and osseous. In no shark or cestracion, e. g., are the gills free, or is there any rudiment of the lungs, such as the air-bladder of most osseous fishes presents; and the lower grade of the skeleton of the sharks is indicated by their position in the so-called 'cartilaginous' order of fishes. When once the skeleton becomes ossified in the class of fishes, little, if anything, can be distinctly predicated of the grade of organization or of development of the fish, as such: in the rest of their organization they are much alike. ·

One of the leading distinctions amongst animals is the position of the skeleton; the great binary division of Lamarck into vertebrata and invertebrata was based upon this distinction; and Cuvier's supplementary labours, which made us better acquainted