An Expository Outline of the "Vestiges of the Natural History of Creation" / With a Notice of the Author's "Explanations:" A Sequel to the Vestiges

by S. Laing

Now it is fossils of the radiata division of the animal kingdom that are found in the lowest stratified rocks, polypiaria and crinodia, the first including various forms of these extraordinary animals (corallines) which still abound in tropical seas, often obstructing the course of the mariner, and even laying the foundation of new continents. The crinoids are an early and simple form of the large family of star-fishes; the animal is little more than a stomach, surrounded by tentacula to provide itself with food, and mounted upon a many-jointed stalk, so as to resemble a flower upon its stem. Along with these in the slate system are a few lowly genera of crustacea, and of a higher class, the mollusca, and the existence of these imply the contemporary existence of certain humbler forms of life, vegetable and animal, for their subsistence, forming a scene approaching to what is found in seas of the present day, excepting that fishes, nor any higher vertebrata, as yet roamed the marine wilds.

The animal species of this era seem to have been few in number, and almost the whole had become extinct before the next group of strata had been formed. In the Silurian deposit the vestiges of life become more abundant, the number of species extended, and important additions made in the traces of sea plants and fishes. Remains of fishes have been detected in rocks immediately over the Aymestry limestone, being apparently the first examples of vertebrated animals which breathed upon our planet. (p. 64). The cephaloda, represented in our era by the nautilus and cuttle-fish, pertain to the Silurian formation, and are the most highly organised of the mollusca, possessing in some families an internal bony skeleton, together with a heart and a head with mandibles not unlike those of the parrot.

In the Old Red Sandstone the same marine specimens are continued with numerous additions. Several of the strata are crowded with remains of fish, showing that the seas in which these beds were deposited had swarmed with that class of inhabitants. The predominating kinds are of an inferior model to the two orders which afterwards came into existence, and still are the principal fishes of our seas; the former are covered with integuments of a considerably different character from the true scales covering the latter, and which orders, from their form of organization, are named stenoid and cycloid.

Up to the present we find proofs of the general uniformity of organic life over the surface of the earth at the time when each particular system of rocks was formed. The types of being formed in the old red as in preceding deposits, are identical in species with the remains that occur in the corresponding class of rocks in Brittany, the Hartz, Norway, Russia, and North America; attesting the similarity and almost universality, if not contemporary character, of terrestrial changes. A few other geological facts may be here mentioned for recollection, and which throw light on the marine animal and vegetable forms of this and preceding eras. First there was comparatively an absence of salt in the early ocean; and next the temperature of the earth is conjectured to have been higher, and perhaps almost uniform throughout. The higher temperature of the primeval times is attributed to the greater proximity or intensity of the globe's internal heat, and which, poured through cracks and fissures of the lately concreted crust, M. BRONGNIART supposes to have been sufficiently great to overpower the ordinary meteorological influences and spread a tropical climate all over its surface.

It must be further borne in mind that as yet no land animals or plants existed, and for this presumable reason, that dry land had not appeared. It is only in the next or carboniferous formation that evidence is traced of island or continent. As a consequence of this emergence there was fresh water; for rain, instead of returning to the sea, as formerly, was collected in channels of the earth and became springs, rivers, and lakes. It was made a receptacle for an advance in organism, and land plants became a conspicuous part of the new creation.

According to the Vestiges of Creation, terrestrial botany began with classes of comparatively simple forms and structure. In the ranks of the vegetable kingdom the lowest place is taken by plants of cellular tissue, and which have no flowers, as lichens, mosses, fungi, ferns, and sea-weeds. Above these stand plants with vascular tissue, bearing flowers, and of which there are two subdivisions: first, plants having one seed-lobe, and in which the new matter is added within, of which the cane and palm are examples; second, plants having two seed lobes, and in which the new matter is added on the outside under the bark, of which the pine, elm, oak, and all the British forest trees are examples. Now the author of the Vestiges states that two-thirds of the plants of this era belong to the cellular kind, but to this one of his ablest critics (Edinburgh Review for July) demurs, asserting that the carboniferous epoch shows a gorgeous flora—that the first fruits of vegetable nature were not rude, ill-fashioned forms, but in magnificence and complexity of structure equal to any living types, and that the forest approached the rank and complicated display of a tropical jungle, where the prevalence of great heat with great moisture, combined with the fact that the atmosphere contained a greater proportion of the natural food of plants, must undoubtedly have forcibly stimulated vegetation, and in quantity and luxuriance of growth, if not fineness of organization, produced it in rich abundance. The earth, it is likely, was one vast forest, which would perform a most important part for the good of its future inhabitants, helping to purge the air of its excess of carbonic acid, by which the earth's surface would be prepared for its new occupants.

The animal remains of this era are not numerous in comparison with those that go before or follow. Contrary to what the author of the Vestiges supposes (p. 111), insects were already buzzing in the air; there were, however, no crawling reptiles on the ground, and it is a doubtful point whether birds cheered the ancient forests with their song. But fishes reached their most perfect organic type. They were the lords of creation, and had a structure in conformity with their high office. Since then the class has increased in its species, but has degenerated to a less noble type.

In the next formation, the New Red Sandstone, reptiles make their appearance. They are considered next to fishes in the zoological scale. So nearly are they sometimes connected, that it is doubtful to which class they belong. Many reptiles are also amphibious, adapted either to water or land. The surface of the globe abounded in large flat, muddy shores, and was suited to the new order of visitants called into existence.

In the Oolite System, mostly consisting of calcareous beds, mammals make their appearance. Some additions were made to the reptile form. One animal (the behemite) appeared, but terminated in the next era. In the following series of rocks mammals increase in abundance. The advance in land animals is less marked, but considerable in the tertiary strata. The tapir forms a conspicuous type. One animal of the kind was eighteen feet long, and had a couple of tusks turning down from the lower jaw, by which it could attach itself, like the walrus, to a bank, while its body floated in the water. Many animals of a former period disappear, and are replaced by others belonging to still existent families—elephant, hippopotamus, and rhinoceros—though extinct as species. Some of these forms are startling from their size. The great mastadon was a species of elephant living on aquatic plants, and reaching the height of twelve feet. The mammoth was another elephant, and supposed to have survived till comparatively recent times. The megatherium is an incongruity of nature, of gigantic proportions, yet ranking in a much humbler order than the elephant, that of the edenta, to which the sloth, ant-eater, and armadilla belong. The megatherium had a skeleton of enormous solidity, with an armour-clad body, and five toes, terminating in huge claws to grasp the branches on which it fed. Finally, beside the dog, cat, squirrel, and bear, we have offered to us, for the first time, oxen, deer, camel, and other specimens of the rumantia. Traces of the quadrumane, or monkey, have been found in the older tertiaries of France, India, and England. So that we may now be said to have arrived at the zoological forms not long antecedent to the appearance of the chief of all, bimana, or man, and shall here pause to consider the conclusions of the author of the Vestiges of Creation on the origin of the organic existences that have been successively exhibited.

It will be convenient, however, first to introduce a synoptic view of the evolutions of the earth as set forth in this and the preceding section. For this purpose the author has introduced a parallel table, exhibiting on one side a scale of animal life beginning with the humblest and ascending to the highest species; and on the other side the successive series of rock formations, in which their fossiliferous remains have been found up to the present superficial deposits of the globe. Objections have been made to the correctness of the author's analogies, scale, and his classification of animals, the chief of which will be adverted to in the next section; but the table is essential, as presenting at one view an outline of the hypothesis he has sought to establish.