And abundant; and we now know, that while they were, as their name indicates, dragons to the weaker insects, they themselves were devoured by dragons as truly such as were ever yet feigned by romancer of the middle ages. Ants were also common, with crickets, grasshoppers, bugs both of the land and water, beetles, twowinged flies, and, in species distinct from the preceding carboniferous ones, the disgusting cockroaches. for the first time amid the remains of a flora that seems to have had its few flowers,-though flowers could have formed no conspicuous feature in even an Oolitic landscape, we detect, in a few broken fragments of the wings of butterflies, decided trace of the flowersucking insects. Not, however, until we enter into the great Tertiary division do these become numerous. The first bee makes its appearance in the amber of the Eocene, locked up hermetically in its gem-like tomb, -an embalmed corpse in a crystal coffin,-along with fragments of flower-bearing herbs and trees. The first of the Bombycidæ too,-insects that may be seen suspended over flowers by the scarce visible vibrations of their wings, and sucking the honied juices by means of their long slender trunks, also appear in the amber, associated with moths, butterflies, and a few caterpillars. Bees and butterflies are present in increased proportions in the latter Tertiary deposits; but not until that terminal creation to which we ourselves belong was ushered on the scene did they receive their fullest development. There is exquisite poetry in Wordsworth's reference to "the soft murmur of the vagrant bee," "A slender sound, yet hoary Time Doth to the soul exalt it with the chime Of all his years; a company Of ages coming, ages gone, Nations from before them sweeping." And yet, mayhap, the naked scientific facts of the his tory of this busy insect are scarcely less poetic than the pleasing imagination of the poet regarding it. They tell that man's world, with all its griefs and troubles, is more emphatically a world of flowers than any of the creations that preceded it; and that as one great family -the grasses were called into existence, in order, apparently, that he might enter in favouring circumstances upon his two earliest avocations, and be in good hope a keeper of herds and a tiller of the ground; and as another family of plants-the Rosacea-was created in order that the gardens which it would be also one of his vocations to keep and to dress should have their trees"good for food and pleasant to the taste;" so flowers in general were profusely produced just ere he appeared, to minister to that sense of beauty which distinguishes him from all the lower creatures, and to which he owes not a few of his most exquisite enjoyments. The poet accepted the bee as a sign of high significance: the geologist also accepts her as a sign. Her entombed remains testify to the gradual fitting up of our earth as a place of habitation for a creature destined to seek delight for the mind and the eye as certainly as for the grosser senses, and in especial marks the introduction of the stately forest trees, and the arrival of the delicious flowers. And, "Thus in their station lifting toward the sky Sweet flowers: what living eye hath viewed Their course, or genial showers descend." LECTURE SECOND. THE PALEONTOLOGICAL HISTORY OF ANIMALS. AMID the unceasing change and endless variety of nature there occur certain great radical ideas, that, while they form, if I may so express myself, the groundwork of the change,-the basis of the variety,-admit in themselves of no change or variety whatever. They constitute the aye-enduring tissue on which the ever-changing patterns of creation are inscribed: the patterns are ever varying; the tissue which exhibits them for ever remains the same. In the animal kingdom, for instance, the prominent ideas have always been uniform. However much the faunas of the various geologic periods may have differed from each other, or from the fauna which now exists, in their general aspect and character, they were all, if I may so speak, equally underlaid by the great leading ideas which still constitute the master types of animal life. And these leading ideas are four in number. First, there is the star-like type of life,-life embodied in a form that, as in the corals, the sea-anemones, the seaurchins, and the star-fishes, radiates outwards from a centre; second, there is the articulated type of life, -life embodied in a form composed, as in the worms, crustaceans, and insects, of a series of rings united by their edges, but more or less moveable on each other; third, there is the bilateral or molluscan type of life,life embodied in a form in which there is a duality of corresponding parts, ranged, as in the cuttle-fishes, the clams, and the snails, on the sides of a central axis or plane; and fourth, there is the vertebrate type of life,life embodied in a form in which an internal skeleton is built up into two cavities placed the one over the other; the upper for the reception of the nervous centres, cerebral and spinal,—the lower for the lodgment of the respiratory, circulatory, and digestive organs. Such have been the four central ideas of the faunas of every succeeding creation, except perhaps the earliest of all, that of the Lower Silurian System, in which, so far as is yet known, only three of the number existed,-the radiated, articulated, and molluscan ideas or types. That Omnipotent Creator, infinite in his resources,-who, in at least the details of his workings, seems never yet to have repeated himself, but, as Lyell well expresses it, breaks, when the parents of a species have been moulded, the dye in which they were cast,-manifests Himself, in these four great ideas, as the unchanging and unchangeable One. They serve to bind together the present with all the past; and determine the unity of the authorship of a wonderfully complicated design, executed on a groundwork broad as time, and whose scope and bearing are deep as eternity. The fauna of the Silurian System bears in all its three great types the stamp of a fashion peculiarly an |