HISTORY. The history of the scientific study of plants probably begins with their classification by Aristotle and Theophrastus into trees, shrubs, and herbs. The study was, however, scarcely carried any further until in the Sixteenth Cen tury the authors of the oldest herbals. Brunfels, Fuchs. Bock, and others, made a beginning again of the scientific examination of plants. It is true that these old herbalists regarded plants chiefly as "the vehicles of medicinal virtues," and that their chief object was to discover the plants employed by the physicians of antiquity, the knowledge of which had been lost in later times. Unscientific as was the purpose, it never theless led straight to nature and to a descrip tion of the wild plants. As a result of this intimate contact with many plants there was a gradual perception of the truth that plants have many points of resemblance to one another, which have nothing to do with their medicinal powers or their usefulness to man. Thus the idea of natural alliances began, alliances which were distinctly felt but not technically defined.
The first period of classification may be said to have culminated in the so-called 'artificial system' of Linmens (1735). It was by no means the intention of Linnams and his predecessors to propose a merely artificial classification of plants, a sort of ready-reference arrangement; but in their philosophy the natural affinities areindicat ed by certain predetermined„ marks, and therefore may be arbitrarily expressed. The system of Lin meus. which was really a better expression of the system of his predecessors. had such an influence upon botanical science for a hundred years that it deserves some fuller statement. He grouped the plant kingdom into twenty-four classes, based upon the number, relative position, and union of the stamens with regard to each other, and also to the carpels. For example, his Class 1.
Olonandria ) comprises flowers with one sta men, and up to Class X. (Decandria) the classes succeed one another by the increment of a single stamen. Class Xl. ( Hodeeandria) lumps to gether flower; with eleven to nineteen stamens. ('lass XII. (lcosandria) includes twenty or more stamens inserted on the calyx, and Class X111. ( Polyandria 1 includes twenty or more stamens inserted on the receptacle. From this point on the basis shifts, as Class X1V. (Didynamia), stamens didynamous: Class XV. (Tetradyna mia), stamens tetradynamous; Class XVI. ( Mon adelphia), filaments united into one bundle; Class XVII. (Diadelphia), filaments united into two bundles; Class XVIII. (Polyadelphia), fila ments united into more than two bundles; Class XIX. (Syngenesia), anthers united; Class XX. (Gynandria), stamens and pistil united; Class XXI. (Moncecia), flowers staminate and pistil late, the two forms on the same plant: Class XXII. (Dicecia), flowers staminate and pistil late, the two forms on different plants; Class XXIII. (Polygamia), staminate, pistillate, and Xxiii. (Polygamia), staminate, pistillate, and perfect flowers on the same plant; Class XXIV. teryptogamia), flowerless plants.
It can be seen that by this scheme flowering plants may be referred readily to different cate gories, but that many of the categories would not at all represent natural alliances, any more than the accident of the first letter groups words together naturally in a dictionary. During the long use of this great artificial system, a far more natural one was being developed slowly, through the work of such botanists as A. L. Jus sieu (1789), A. P. de Candolle (181S-21), Stephen Endlieher (1S3G-40). A. T. Brongniart (1843), John Lindley (1S46), Alexander Braun ( 1SG4 ) . Bentham and Hooker ( ISG2-18S3 ) , A. W. Eichler (1883), and A. Engler (1892—).