favorite one with thoughtful men in every age of the world. According to the Psalmist, these great "works of the Lord are sought out of all them that have pleasure therein." The Book of Job, probably the oldest writing in existence, is full of vivid descriptions of the wild denizens of the flood and desert; and it is expressly recorded of the wise old Ling, that he "spake of trees, from the cedar tree that is in Lebanon, even unto the hyssop that springeth out of the wall; and also of beasts, and of fowl, and of creeping things, and of fishes." Solomon was a zoologist and botanist; and there is palpable classification in the manner in which his studies are described. It is a law of the human mind, as has been already said, that, wherever a large stock of facts are acquired, the classifying principle steps in to arrange them. "Even the rudest wanderer in the fields," says Dr. Brown, "finds that the profusion of blossoms around him—in the greater number of which he is able himself to discover many striking resemblances may be reduced to some order of arrangement." But, for many centuries, this arranging faculty labored but to little purpose. As specimens of the strange classification that continued to obtain down till comparatively modern times, let us select that of two works which, from the literary celebrity of their authors, still possess a classical standing in letters, Cowley's "Treatise on Plants," and Goldsmith's "History of the Earth and Animated Nature." The plants we find arranged by the poet on the simple but very inadequate principle of size and show. Herbs are placed first, as lowest and least conspicuous in the scale; then flowers; and, finally, trees. Among the herbs, at least two of the ferns-the true maidenhair and the spleenwort -are assigned places among plants of such high standing as sage, mint, and rosemary: among the flowers, monocotyledons, such as the iris, the tulip, and the lily, appear

among dicotyledons, such as the rose, the violet, the sunflower, and the auricula: and among trees we find the palms placed between the plum and the olive; and the yew, the fir, and the juniper, flanked on one side by the box and the holly, and on the other by the oak. Such, in treating of plants, was the classification adopted by one of the most learned of English poets in the year 1657.

Nor was Goldsmith, who wrote more than a century later, much more fortunate in dealing with the animal kingdom. Buffon had already published his great work; and even he could bethink him of no better mode of divid ing his animals than into wild and tame. And in Goldsmith, who adopted, in treating of the mammals, a similar principle, we find the fishes and molluscs placed in advance of the sauroid, ophidian, and batrachian reptiles, - the whale united in close relationship to the sharks and rays,---animals of the tortoise kind classed among animals of the lobster kind, and both among shell fish, such as the snail, the nautilus, and the oyster. And yet Goldsmith was engaged on his work little more than eighty years ago. In fine, the true principles of classification in the animal kingdom are of well nigh as recent development as geologic science itself, and not greatly more ancient in even the vegetable kingdom. It would, of course, be wholly out of place to attempt giving a minute history here of the progress of arrangement in either department; but it can scarce be held that the natural system of plants was other than very incomplete previous to 1789, when Jussieu first enunciated his scheme of classification; nor did it receive its later improvements until so late as 1846, when, after the publication, in succession, of the schemes of De Candolle and Endlicher, Lindley communicated his finished system to the world. And there certainly existed no even tolerably perfect system of zoology until 1816, when the "Animal King

dom" of Cuvier appeared. Later naturalists, such as Agassiz, in his own special department, the history of fishes, and Professor Owen in the invertebrate divisions, have improved on the classification of even the great Frenchman; but for purposes of comparison between the scheme developed in geologic history and that at length elaborated by the human mind, the system of Cuvier will be found, for at least our present purpose, sufficiently complete. And in tracing through time the course of the vegetable kingdom, let us adopt, as our standard to measure it by, the system of Lindley.

Commencing at the bottom of the scale, we find the Thallogens, or flowerless plants which lack proper stems and leaves, a class which includes all the algae. Next succeed the Acrogens, or flowerless plants that possess both stems and leaves, such as the ferns and their allies. Next, omitting an inconspicuous class, represented by but a few parasitical plants incapable of preservation as fossils, come the Endogens, monocotyledonous flowering plants, that include the palms, the liliacea, and several other families, all characterized by the parallel venation of their leaves. Next, omitting another inconspicuous tribe, there follows a very important class, the Gymnogens, — polycotyledonous trees, represented by the coniferæ and cycadaceæ. And, last of all, come the Dicotyledonous Exogens,-a class to which all our fruit, and what are known as our forest trees," belong, with a vastly preponderating majority of the herbs and flowers that impart fertility and beauty to our gardens and meadows. This last class, though but one, now occupies much greater space in the vegetable kingdom than all the others united.

Such is the arrangement of Lindley, or rather an arrange ment the slow growth of ages, to which this distinguished botanist has given the last finishing touches. And let us

now mark how closely it resembles the geologic arrangement as developed in the successive stages of the earth's history.

The most ancient period of whose organisms any trace remains in the rocks seems to have been, prevailingly at

*The horizontal lines in this diagram indicate the divisions of the various geologic systems; the vertical lines the sweep of the various classes or sub-classes of plants across the geologic scale, with, so far as has yet been ascertained, the place of their first appearance in creation; while the double line of type below shows in what degree the order of their occurrence agrees with the arrangement of the botanist. The single point of difference indicated by the diagram between the order of occurrence and that of arrangement, viz., the transposition of the gymnogenous and monocotyledonous classes, must be regarded as purely provisional. It is definitely ascertained that the Lower Old Red Sandstone has its coniferous wood, but not yet definitely ascertained that it has its true monocotyledonous plants; though indications are not awanting that the latter were introduced upon the scene at least as early as the pines or araucarians; and the chance discovery of some fossil in a sufficiently good

least, a period of Thallogens. We must, of course, take into account the fact, that it has yielded no land plants, and that the sea is everywhere now, as of old, the great habitat of the algæ, one of the four great orders into which the Thallogens are divided. There appear no traces of a terrestrial vegetation until we reach the uppermost beds of the Upper Silurian System. But, account for the fact as we may, it is at least worthy of notice, that, alike in the systems of our botanists and in the chronological arrangements of our geologists, the first or introductory class which occurs in the ascending order is this humble Thallogenic class. There is some trace in the Lower Silurians of Scotland of a vegetable structure which may have belonged to one of the humbler Endogens, of which, at least, a single genus, the Zosteraceæ, still exists in salt water; but the trace is faint and doubtful, and, even were it established, it would form merely a solitary exception to the general evidence that the first known period of vegetable existence was a period of Thallogens. The terrestrial remains of the Upper Silurians of England, the oldest yet known, consist chiefly of spore-like bodies, which belonged, says Dr. Hooker, to Lycopodiacea,- an order of the second or acrogenic class. And, in the second great geologic period, - that of the Old Red Sandstone, we find this second class not inadequately represented. In its lowest fossiliferous beds we detect a Lycopodite which not a little resembles one of the commonest of our club mosses,- Lycopodium clavatum,- with a minute fern and a large stri ated plant resembling a calamite, and evidently allied to an existing genus of Acrogens, the equisetaceae. In the Middle Old Red Sandstone there also occurs a small fern, with

state of keeping to determine the point may, of course, at once retranspose the transposition, and bring into complete correspondence the geologic and botanic arrangements.