The study of plants and animals seems to have been a 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 king, 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.