Page:Popular Science Monthly Volume 50.djvu/188

174 shown in the view of the Botanical Laboratory exhibits the formal style of planting which prevailed in earlier times.

The Chelsea garden is situated near the Thames, about two miles south from Hyde Park. It was formed by the Apothecaries' Guild of London, for the growth of plants for commercial purposes. Later it was converted to its present use, that of furnishing material to illustrate lectures in pharmacy and medicine.Surrounded on all sides by brick buildings, and shaded by smoke and fog, the rectangular plots of officinal plants exhibit very strikingly the deleterious effects of an atmosphere laden with acids. The would-be visitor to this quaint old place must arm himself with an admission card obtained from the Apothecaries' Society, and from the creaking formalities attendant upon the granting of such permission by unaccustomed but polite officials it may be inferred that the casual sight-seer does not often find his way into the place.

During the period inclusive of the foundation of the last-named institutions plants began, however, to be considered from another point of view—from a strictly scientific standpoint, and as independent organisms. While the Aristotelian school studied plants in a manner closely approaching that of the present time, yet this beginning of biological science had no logical continuation, and during many succeeding centuries was completely lost to sight. In the latter half of the sixteenth century two new forces were manifest in the development of these institutions. Many of the wealthier class who had private gardens began to enlarge them by the addition of species because of their rarity, or because they were brought from some foreign country, and in many instances special collections were made chiefly for this purpose alone. Thus it may be seen that beyond the useful properties of plants,perhaps the first truly scientific idea of them concerned in a crude way some of the principles of geographical distribution. This phase of the subject received an increasing attention, and finally assumed form and order upon the introduction of the Linnæan system of classification into Germany and that of Jussieu into France.

Before this, however, a still more important development in the method of study of plants had ensued, as is shown distinctly in the botanical writings of the latter half of the sixteenth century. The all-important fact of the natural affinities of plants had gradually assumed distinctness—an idea not within the grasp of any one of the herbalists of the time, whose accumulating and repeated descriptions of individual species gave rise to the perception of resemblance and difference in forms, and finally to the idea of natural relationship. This idea finally became paramount: “All the foreign matter introduced into the descriptions of plants by medical superstition and practical considerations