A remarkable peculiarity in the mammalian remains of the tertiary period is the total absence of the ruminating animals, which do not appear until the modern epoch, when we recognize them at once as the companions and useful contributors to the comforts of man. These still retain “the names” which Adam bestowed upon them. The more ancient creations rejoice in the mythical nomenclature of science, of which between fifty and sixty species have been determined. The greater proportion are from the Paris basin; but the district under review contains, in its lower and middle divisions, the remains of some of the more remarkable of the group—as the Palæotherium, Anoplotherium, Lophiodon, Chœropotamus, Didelphis, Balœenodon, and the huge Mastodon.—These animals are specifically different from everything now in existence; even Macacus Eocenus will find no lineal descendant in Ceylon, Madagascar, or the Cape; and no Celtic pedigree will meet the case. The race have left our island, and departed from the earth; and to restore them in imagination, we must seek their nearest analogies in the impenetrable fastnesses and prairies of unreclaimed nature.
5. Birds are distinctly traceable in this formation. The Eocene clays of the Isle of Sheppey have produced materials sufficiently indicative of the class, in which the true affinities of the aerial inhabitants are detected, and a new genus completely established. The specimens found bear a resemblance to the osteology of the smaller kinds of vultures, and one has been designated Lithornis Vulturinus. The ‘Icones fossilium sectiles’ of Kœnig contains a description of some other ornitholites found in the same locality, considered by the author as belonging to a natatorial or long-toed bird, and denominated Bucklandium Diluvii. The Paris basin is more fruitful in these fossils than the London; from these several species have been determined—more or less allied to the pelican, the sea-lark, curlew, woodcock, buzzard, owl, and quail; thus clearly establishing the link in the chain of being, but still at a wide interval from the gay choristers and domesticated tribes which minister so much to the solace and happiness of man. The geologist traces the connection, and sees in the expanse of ages, as race after race emerge upon the scene, a gradual preparation and tendency of all things to a final result; sea, earth, and air successively possessed by creatures approximating as they advance to those of the human epoch; and man proudly or presumptuously concludes, that all has been “worked solely for his good.” But as the poet has sung—may we not ask, and ask concerning the humblest life which man often despises and as often terribly destroys, but which is never overlooked by Him who made man and all things, and whose tender care is over all his works?—
“Is it for thee, the lark ascends and sings?
Joy tunes his voice, joy elevates his wings.
Is it for thee, the linnet pours his throat?
Loves of his own, and raptures swell the note.
Is thine alone, the seed that strews the plain?
The birds of Heaven shall vindicate their grain.”
6. And in the Flora which then decked the plains, fringed the marshes, or clothed the heights, “the birds of heaven” had ample provision in seed, fruit, and herbage for all their wants. Remarkable indeed the adaptation of the animal tribes referred to in the previous section to the lacustrine condition of the surface which still so generally prevailed. The plants of the period are such as are now exclusively confined to warm or tropical latitudes. The palms and cocoa-nut bearing trees are abundant and of different kinds. One family belongs to the Nipadites, which are found in Japan and the Spice Islands, generally in the estuaries of rivers, or along the tracts of damp marshy grounds. The lovely Acacia was here naturalized. Pepper, dates, and cucumbers added to the variety of the sylvan banquet, which tall branching pines shaded from the scorching heat. If we are no longer in possession of the luxurious fruits and condiment-bearing plants of this early age, the change has led to other and better productions. For deep lakes we have these verdant meadows and corn plains; the stagnant marshes are drained of their mephitic vapors; the theroid monsters are supplanted by the laboring ox and the industrial horse; and with all the arts flourishing, and carried to the highest pitch along her borders, the proudest achievements of science wafted on her bosom—the “fruitful Thame” may challenge the nations of the earth for every product which climate yields or genial suns ripen.
Such was the dawn or introduction to the present order of things. In the language of geology it is called the eocene age of the world, because it approaches in its organic productions to those which are now existing, and containing a very few recent species, not more than three or four per cent. Nature did not all at once leap from one epoch to another. In the tertiary deposits there is evidence of successive creations, rests and pauses, as it were, before the final and crowning consummation of her works. More and more analogies begin to manifest themselves in the ascending series of the group. The Miocene, or middle period, develops a yet larger proportion, though not a majority, of the present inhabitants of the sea. The Pleiocene arrangements follow; and in the shells and terrestrial products of this group the modern characters and types are still more clearly discernible. When we reach the highest members, the difficulties of separation from the modern deposits begin to multiply; the mineral qualities and mere earthy beds are not distinguishable; while, on the other hand, in all the animal forms and huge colossal proportions of Mastodons and Theriums, there are the unequivocal markings of an extinct anterior age.