CHAPTER II

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ARTIFICIAL SYSTEMS AND TERMINOLOGY OF ORGANS FROM CESALPINO TO LINNAEUS.

1583-1760.

While botany was being developed in Germany and the Netherlands in the manner described in the previous chapter, and long before this process of development reached its furthest point in Kaspar Bauhin, ANDREA CESALPINO in Italy was laying down the general plan, on which the further advance of descriptive botany was to proceed in the 17th and till far into the 18th century; all that was done in the 17th century in Germany, England, and France towards furthering morphology and systematic botany was done with a reference to Cesalpino’s principles, whether these were accepted and made use of, or whether it was sought to refute them. This connection with Cesalpino became gradually less close and less obvious, being concealed by new points of view and by the increase of material for observation; but Cesalpino’s ideas on the theoretical principles of systematic botany and the nature of plants appear so plainly, even in the views of Linnaeus, that no one can read both authors without lighting not unfrequently upon passages in Linnaeus’ ‘Fundamenta’ or in his ‘Philosophia Botanica,’ which remind him of Cesalpino, and even upon sentences borrowed from him. As we saw in Kaspar Bauhin the close of the course of development commenced by Fuchs and Bock, so we may regard Linnaeus as having built up and completed the edifice of doctrine founded by Cesalpino.

Cesalpino comes before us, in strong contrast with the simple-minded empiricism of the German fathers of botany, as the thinker in presence of the vegetable world. Their main task was the amassing descriptions of individual plants. Cesalpino made the material gathered by experience the subject of earnest reflection; he sought especially to obtain universals from particulars, important principles from sensuous perceptions; but as his forms of thought were entirely Aristotelian, it was inevitable that his interpretation of the facts should introduce into them much that would have to be got rid of subsequently by the inductive method. Cesalpino differs also from the German botanists in another respect; he did not rest satisfied with the general impression produced by the plants, but carefully examined the separate parts and paid attention to the small and concealed organs; he was the first who converted observation into real scientific research; and thus we find in him a remarkable union of inductive natural science and Aristotelian philosophy, a mixture which gives a peculiar character to the theoretical efforts of his successors down to Linnaeus.

Cesalpino was moreover much before his time in his mode of contemplating the vegetable kingdom, seeking always for philosophical combinations and comprehensive points of view. His work which appeared in 1583 exercised no perceptible influence on his contemporaries; a trace of such influence only may be seen in Kaspar Bauhin thirty or forty years later, while the work of the botanists who followed Bauhin down to 1670 was confined everywhere to increasing the knowledge of individual plants. With this object travels were undertaken after 1600 to all parts of the world; many new botanic gardens were added to the few which had been founded in the 16th century—as at Giessen in 1617, at Paris in 1620, at Jena in 1629, at Oxford in 1632, at Amsterdam in 1646, at Utrecht in 1650. Instead of endeavouring to embrace with their labours the whole vegetable kingdom, botanists preferred to devote themselves to the examination of single districts. This gave rise to the first local floras (the word flora, however, was first introduced by Linnaeus in the next century), and of these Germany especially soon produced a considerable number; a flora of Altorf was published by Ludwig Jungermann in 1615, of Ingolstadt by Albert Menzel in 1618, of Giessen by Jungermann in 1623, of Dantzic by Nicolaus Oelhafen in 1643, of Halle by Carl Scheffer in 1662, of the Palatinate by Frank von Frankenau in 1680, of Leipsic by Paul Ammann in 1675, of Nuremberg by J. Z. Volkamer in 1700.

But though travel, catalogues in local floras, and the cultivation of plants in botanic gardens promote knowledge of very varied kind, yet this remains scattered about among descriptions of plants, until at last a writer with powers of combination and wider and deeper glance endeavours to gain some general conclusions from them. Such attempts we first meet with late in the second half of the 17th century in Morison, Ray, Bachmann (Rivinus), Tournefort, and others, who took up Cesalpino’s principles after they had lain neglected for almost a hundred years, and indeed were almost forgotten by botanists.

In the dearth of higher scientific efforts during this period, the describing of plants and cataloguing of species prolonged a somewhat pitiful existence. This describing, a work of great usefulness in the fathers of German botany, was now become by perpetual repetition a mechanical labour; all that was to be gained in this way had already been gained by de l’Obel and Bauhin. This sterility which followed upon the fruitful beginnings of the 16th century was general; neither in Germany nor Italy, neither in France nor England, did the botanists produce anything of importance. The representatives of the science did not count among the more highly gifted or among the thinkers of their time; and so content with the minor work of collecting and cataloguing plants, and with endeavouring to know all plants as far as possible by name, they lost whatever capacity they may have possessed for more difficult operations of the mind simply by not attempting them.

There was one man indeed in Germany who studied the vegetable kingdom in the first half of the 17th century in the spirit of Cesalpino before him, but who, like Cesalpino, found no honour among contemporary botanists. This man was the well-known philosopher Joachim Jung, who invented a comparative terminology for the parts of plants, and occupied himself with critical enquiries into the theory of the system, the naming of species and other subjects, embodying their results in a long array of aphorisms. Free from the genius-stifling burden which the knowledge of individual species had become, a man possessed of varied accomplishments and a well-trained mind, Jung was better qualified than the professed botanists to see what was wanted in botany and would advance it—a phenomenon more than once repeated in the history of the science. But his results remained unknown to all except his immediate pupils, till Ray admitted them into his great work on plants in 1693, and made them the foundation of his own theoretical botany. Enriched by Ray’s good morphological remarks, Jung’s terminology passed to Linnaeus, who adopted it as he adopted every thing useful that literature offered him, improving it here and there, but impairing its spirit by his dry systematising manner.

The labours of the botanists of Germany and the Netherlands during the 17th century, which culminated in Kaspar Bauhin, were not without important influence upon the development of systematic botany which began with Cesalpino. When Cesalpino wrote the work which forms an epoch in the science, he was perhaps unacquainted with the natural classification of de l’Obel (1576); at least there is nothing in his book which shows that he had seen it; it appears even as though he had made the discovery independently, that there is an actual connection of relationship among plants expressed in their organisation as a whole; it is at any rate certain that this fact assumed from the first an entirely different expression in his system from that which it received at the hands of de l’Obel and Bauhin, inasmuch as he was not guided by an indistinct feeling for resemblances, but believed that he could establish on predetermined grounds a system of marks, by which the objective relationship must be recognised. If Cesalpino was thus in advance of the German botanists, since he endeavoured to express with clearness and on principle that which they only felt indistinctly, he was at the same time treading a dangerous path, and one which led succeeding botanists astray till the time of Linnaeus,—the path which must always lead to artificial classifications, since the natural system can never be laid down upon _a priori_ principles of division. Through this labyrinth, in which botanists down to Linnaeus wandered fruitlessly hither and thither, there remained one guide consistently pointing to the goal to be attained, namely, the feeling for natural affinity first vividly apprehended by the German botanists, and expressed by them to some extent in their classifications. And when at last Linnaeus and Bernard de Jussieu made the first feeble attempts at a natural arrangement, it was the same indistinct perception which asserted itself in them as in de l’Obel and Bauhin, and enabled them to see that the path hitherto trodden could only lead astray.

The period in the development of descriptive botany which begins with Cesalpino and reaches to Linnaeus may accordingly be perhaps best characterised by saying, that botanists sought to do justice to natural affinities by means of artificial classifications, till at length Linnaeus clearly perceived the contradiction involved in this method of proceeding. But inasmuch as Linnaeus left it to the future to work out the natural system, and arranged the plants which he described in a confessedly artificial manner, he so far marks rather the close of a previous condition of the science than the beginning of modern botany.

These introductory observations will have supplied the reader with the thread which will guide him through the following account of the more prominent points in the history of botanical science from Cesalpino to Linnaeus.

The often-quoted work of Andrea Cesalpino[17], ‘De plantis libri XVI,’ appeared in Florence in the year 1583. If the value of the contemporary German botanists lies pre-eminently in the accumulation of descriptions of individual plants, and these, it is true, occupy fifteen books of Cesalpino’s work, it is on the contrary the introduction in the first book, a discussion of the general theory of the subject, which in his case is of much the higher importance for the history of botany. This contains in thirty pages a full and connected exposition of the whole of theoretical botany, and though based on broad and general views is at the same time extremely rich in matter conveyed in a very concise form. The different branches into which the subject has since been divided are here united into an inseparable whole; morphology, anatomy, biology, physiology, systematic botany, terminology are so closely combined, that it is difficult to explain Cesalpino’s views on any one more general question without at the same time touching on a variety of other matters. Three things more especially characterise this introductory book; first, a great number of new and delicate observations; secondly, the great importance which Cesalpino assigns to the organs of fructification as objects of morphological investigation; lastly, the way in which he philosophises in strictly Aristotelian fashion on the material thus gained from experience. If this treatment has produced a work beautiful in style and fascinating to the reader, if the whole subject is vivified by it while each separate fact gains a more general value, it is on the other hand apparent that the writer is often led astray by the well-known elements of the Aristotelian philosophy, which are opposed to the interests of scientific investigation. Mere creations of thought, the abstractions of the understanding, are treated as really existent substances, as active forces, under the name of principles; final causes appear side by side with efficient; the organs and functions of the organism exist either _alicujus gratiâ_ or merely _ob necessitatem_; the whole account is controlled by a teleology, the influence of which is the more pernicious because the purposes assumed are supposed to be acknowledged and self-evident, plants and vegetation being conceived of as in every respect an imperfect imitation of the animal kingdom. It was moreover a necessary consequence of the treatment of his material adopted by Cesalpino, that his ignorance of the sexuality of plants and of the use of leaves as organs of nutrition led him to false and mischievous conclusions; this defect of knowledge would have been of less importance in a purely morphological consideration of plants, as we shall see presently in Jung; but with Cesalpino morphological and physiological considerations are so mixed up together, that a mistake in the one direction necessarily involved mistakes in the other.

These remarks on Cesalpino’s method may be illustrated by some examples tending to show how closely he attaches himself to Aristotle, and how certain Aristotelian conceptions, the origin of which has not been sufficiently regarded, passed through him into later botanical speculation. We shall recur in the History of Physiology to Cesalpino’s views on nutrition, and to his rejection of the doctrine of sexuality in plants.

‘As the nature of plants,’ so begins Cesalpino’s book, ‘possesses only that kind of soul by which they are nourished, grow, and produce their like, and they are therefore without sensation and motion in which the nature of animals consists, plants have accordingly need of a much smaller apparatus of organs than animals.’ This idea reappears again and again in the history of botany, and the anatomists and physiologists of the 18th century were never weary of dilating on the simplicity of the structure of plants and of the functions of their organs. ‘But since,’ continues Cesalpino, ‘the function of the nutritive soul consists in producing something like itself, and this like has its origin in the food for maintaining the life of the individual, or in the seed for continuing the species, perfect plants have at most two parts, which are however of the highest necessity; one

## part called the root by which they procure food; the other by which

they bear the fruit, a kind of foetus for the continuation of the species; and this part is named the stem (‘caulis’) in smaller plants, the trunk (‘caudex’) in trees.‘

This in the main correct conception of the upright stem as the seed-bearer of the plant was also long maintained in botany. We should observe also that the production of the seed is spoken of as merely another kind of nutrition, a notion which afterwards prevented Malpighi from correctly explaining the flower and fruit, and in a modified form led Kaspar Friedrich Wolff in 1759 to a very wrong conception of the nature of the sexual function. The next sentence in Cesalpino takes us into the heart of the Aristotelian misinterpretation of the plant, according to which the root answers to the mouth or stomach, and must therefore be regarded in idea as the upper part although it is the lower in position, and the plant would have to be compared with an animal set on its head, and the upper and lower parts determined accordingly: ‘this part (the root) is the nobler (‘superior’) because it is prior in origin and sunk in the ground; for many plants live by the roots only after the stem with the ripe seeds has disappeared; the stem is of less importance (‘inferior’) although it rises above the ground; for the excreta, if there are any, are given off by means of this part; it is, therefore, with plants as with animals as regards the expressions ‘pars superior’ and ‘inferior.’ When indeed we take into consideration the mode of nourishment, we must define the upper and the lower in another way; since in plants and animals the food mounts upward (for that which nourishes is light because it is carried upwards by the heat), it was necessary to place the roots below and to make the stem go straight upwards, for in animals also the veins are rooted in the lower part of the stomach, while their main trunk ascends to the heart and the head.’ Here, in genuine Aristotelian fashion, the facts are forced into a previously constructed scheme.

Cesalpino’s discussion of the seat of the soul in plants is of special interest in connection with certain views of later botanists. ‘Whether any one part in plants can be assigned as the seat of the soul, such as the heart in animals, is a matter for consideration—for since the soul is the active principle (‘actus’) of the organic body, it can neither be ‘tota in toto’ nor ‘tota in singulis partibus,’ but entirely in some one and chief part, from which life is distributed to the other dependent parts. If the function of the root is to draw food from the earth, and of the stem to bear the seeds, and the two cannot exchange functions, so that the root should bear seeds and the shoot penetrate into the earth, there must either be two souls different in kind and separate in place, the one residing in the root, the other in the shoot, or there must be only one, which supplies both with their peculiar capabilities. But that there are not two souls of different kinds and in a different part in each plant may be argued thus; we often see a root cut off from a plant send forth a shoot, and in like manner a branch cut off send a root into the ground, as though there were a soul indivisible in its kind present in both parts. But this would seem to show that the whole soul is present in both parts, and that it is wholly in the whole plant, if there were not this objection that, as we find in many cases, the capabilities are distributed between the two parts in such a way that the shoot, though buried in the ground, never sends out roots, for example in Pinus and Abies, in which plants also the roots that are cut off perish.’ This, he thinks, proves that there is only one soul residing in root and stem, but that it is not present in all the parts; in a further discussion he seeks to discover the true seat of the soul. He points out an anatomical distinction between the shoot and the root; the root consists of the rind and an inner substance which in some cases is hard and woody, in others soft and fleshy. In the stem on the other hand there are three constituent parts; outside the rind, inside the pith, between the two a body which in trees is called the wood. This, on the whole, correct distinction between stem and root is followed by a thoroughly Aristotelian deduction.

‘Since then in all creatures’ (we must remark, that this is assuming a point which has yet to be proved in the case of the half of living creatures) ‘nature conceals the principle of life in the innermost parts, as the entrails in animals, it is reasonable to conclude that the principle of life in plants is not in the rind, but is more deeply hidden in the inner parts, that is, in the pith, which is found in the stem and not in the root. That this was the opinion of the ancients we may gather from the name, for they called this part in plants the heart (‘cor’), or brain (‘cerebrum’ or ‘matrix’), because from this

## part in some degree the principle of foetification (the formation of

the seed) is derived.’ Here we see why the seed must, according to Cesalpino, have its origin in the pith; the idea was loyally repeated after him by Linnaeus, as we shall see hereafter. The argument, which is a long one, ends with the sentence: ‘There are then two chief parts in plants, the root and the ascending part; therefore the most suitable spot for the heart of plants seems to be in the central part, namely, where the shoot joins on to the root. There appears also at this spot a certain substance differing both from the shoot and from the root, softer and more fleshy than either, for which reason it is usually called the cerebrum; it is edible in many plants while they are young.’ We shall see below how important a part this seat of the soul of the plant, brought to light with such difficulty and with all appliances of scholasticism, is intended to play in Cesalpino’s system, and how by this _a priori_ path he was led to the use of the position of the embryo in the seed as his principle of division. It may be remarked here that the point of union between the root and the stem, in which Cesalpino placed the seat of the plant-soul, afterwards received the name of root-neck (collet); and though the Linnaean botanists of the 19th century were unaware of what Cesalpino had proved in the 16th, and did not even believe in a soul of plants, they still entertained a superstitious respect for this part of the plant, which is really no part at all; and this, it would seem, explains the fact, that an importance scarcely intelligible without reference to history was once attributed to it, especially by some French botanists. To return once more to Cesalpino’s ‘cor,’ he is not much troubled by the circumstance that plants can be reproduced from severed portions; in true Aristotelian manner he says that although the principle of life is actually only one, yet potentially it is manifold. Ultimately a ‘cor’ is found in the axil of every leaf, by which the axillary shoot is united with the pith of the mother-shoot, and finally, in direct contradiction to the previous proof that the crown of the root is the seat of the plant-soul, it is distinctly affirmed in