It would carry me too far, were I to attempt to give anything more than the most cursory sketch of the animals of the Tertiary age; and, indeed, they are so well known, and have been so fully represented in text-books, that I fear some of my readers may think even now that I have dwelt too long upon them. Monkeys were unquestionably introduced upon earth before the close of the Tertiaries; some bones have been found in Southern France, and also on Mount Pentelicus in Greece, in the later Tertiary deposits; but these remains have not yet been collected in sufficient number to establish much more than the fact of their presence in the animal creation at that time. I do not offer any opinion respecting the fossil human bones so much discussed recently, because the evidence is at present too scanty to admit of any decisive judgment concerning them. It becomes, however, daily more probable that facts will force us sooner or later to admit that the creation of man lies far beyond any period yet assigned to it, and that a succession of human races, as of animals, have followed one another upon the earth. It may be the inestimable privilege of our young naturalists to solve this great problem, but the older men of our generation must be content to renounce this hope; we may have some prophetic vision of its fulfilment, we may look from afar into the land of promise, but we shall not enter in and possess it. [Illustration] [Illustration] [Illustration] The other great types of the Animal Kingdom are very fully represented in the Tertiaries, and in their general appearance they approach much more closely those of the present creation than of any previous epochs. Professor Heer has collected and described the Tertiary Insects in great number and variety; and the Butterflies, Bugs, Flies, Grasshoppers, Dragon-Flies, Beetles, etc., described in his volumes, would hardly be distinguished from our own, except by a practised entomologist. Among Crustacea, the Shrimp-like forms of the earlier geological epochs have become much less conspicuous, while Crabs and Lobsters are now the prominent representatives of the class. Among Mollusks, the Chambered Shells, hitherto so numerous, have become, as they now are, very few in comparison with the naked Cephalopods. The Nautili, however, resemble those now living in the Pacific Ocean; and some fragments of the Paper-Nautilus have been found, showing that this delicate shell was already in existence. There is one very peculiar type of this class, belonging to the Tertiaries, which should not be passed by unnoticed. It partakes of the character both of the Cretaceous Belemnites and of the living Cuttle-Fish, and is known as the Spirulirostra. Another very characteristic group among the Tertiary Shells is that of the Nummulites, formerly placed by naturalists in immediate proximity with the Ammonites, on account of their internal partitions. This is now admitted to have been an error; their position is not yet fully