Any great advance on Bauhin’s descriptions could hardly be expected during the period which we are discussing, since it closed before the nature of the essential parts of the flower was really understood. It was not until 1682 that the fact that the stamens are male organs was pointed out in print by Nehemiah Grew, though he himself attributed this discovery to Sir Thomas Millington, a botanist otherwise unknown. Gerard’s account of the stamens and stigma of the Potato as a “pointell, yellow as golde, with a small sharpe greene pricke or point in the middest thereof,” vague as it seems to the twentieth-century botanist, is by no means to be despised, when we remember that the writer was handicapped by complete ignorance of the function of the structures which he saw before him.
A further hindrance to improvement in plant description was the lack of a methodical terminology. As we have already shown, both Fuchs and Dodoens attempted glossaries of botanical terms, but these do not seem to have become an integral part of the science. It is a common complaint among non-botanists at the present day, that the subject has become incomprehensible to the layman, owing to the excessive use of technical words. There is, no doubt, some truth in this statement, but, on the other hand, a study of the writings of the earlier botanists makes it clear that a description of a plant couched in ordinary language—in which the botanical meaning of the terms employed has been subjected to no rigid definition—often breaks down completely on all critical points.
It is to Joachim Jung and to Linnæus that we owe the foundations of the accurate terminology, now at the disposal of the botanist when he sets out to describe a new plant. The published work of these two writers belongs, however, to the late seventeenth and eighteenth centuries, and is thus outside the scope of the present volume.
CHAPTER VI
THE EVOLUTION OF PLANT CLASSIFICATION
N the earliest European works on natural history—those of the Aristotelian school—we meet with an attempt to classify the different varieties of plants. It was inevitable that the writers of this school should make such an attempt, since no mind trained in Greek philosophy could be content to leave a science in the condition of a mere chaos of isolated descriptions. At first the most obvious distinction, that of size, was used as the chief criterion whereby to separate the different groups of the vegetable kingdom. In the ‘History of Plants’ of Theophrastus, we find Trees, Shrubs, Bushes and Herbs treated as definite classes, within which, cultivated and wild plants are distinguished. Other distinctions of lower value are made between evergreen and deciduous, fruiting and fruitless, and flowering and flowerless plants.
Albertus Magnus, who kept alive in the Middle Ages the spirit of Aristotelian botany, was more advanced than Theophrastus in his method of classification. It is true that he divides the vegetable world into Trees, Shrubs, Undershrubs, Bushes, Herbs and Fungi, but at the same time he points out that this is an arbitrary scheme, since these groups cannot always be distinguished from one another, and also because the same plant may belong to different classes at different periods of its life. A study of the writings of Albertus reveals the fact that he had in mind, though he did not clearly state it, a much more highly evolved system, which may be diagrammatically represented as follows. The modern equivalents of his different groups are shown in square brackets:—