nefort, which was governed by the corolla; for number is more definite than irregular form. It was more readily employed than any of those which depend on the fruit, for the flower is a more obvious object, and more easily examined. Still, it can hardly be doubted, that the circumstance which gave the main currency to the system of Linnæus was its physiological signification: it was the Sexual System. The relation of the parts to which it directed the attention, interested both the philosophical faculty and the imagination. And when, soon after the system had become familiar in our own country, the poet of The Botanic Garden peopled the bell of every flower with "Nymphs" and "Swains,” his imagery was felt to be by no means forced and far-fetched. The history of the doctrine of the sexes of plants, as a point of physiology, does not belong to this place; and the Linnæan system of classification need not be longer dwelt upon for our present purpose. I will only explain a little further what has been said, that it is, up to a certain point, a natural system. Several of Linnæus's classes are, in a great measure, natural associations, kept together in violation of his own artificial rules. Thus the class Diadelphia, in which, by the system, the filaments of the stamina should be bound together in two parcels, does, in fact, contain many genera which are monadelphous, the filaments of the stamina all cohering so as to form one bundle only; as in Genista, Spartium, Anthyllis, Lupinus, &c. And why is this violation of rule? Precisely because these genera all belong to the natural tribe of Papilionaceous plants, which the author of the system could not prevail upon himself to tear asunder. Yet in other cases Linnæus was true to his system, to the injury of natural alliances, as he was, for instance, in another portion of this very tribe of Papilionacea; for there are plants which undoubtedly belong to the tribe, but which have ten separate stamens; and these he placed in the order Decandria. Upon the whole, however, he inclines rather to admit transgression of art than of nature. The reason of this inclination was, that he rightly considered an artificial method as instrumental to the investigation of a natural one; and to this part of his views we now proceed. Sect. 5.-Linnæus's Views on a Natural Method. THE admirers of Linnæus, the English especially, were for some time in the habit of putting his Sexual System in opposition to the Natural Method, which about the same time was attempted in France. And as they often appear to have imagined that the ultimate object of botanical methods was to know the name of plants, they naturally preferred the Swedish method, which is excellent as a finder. No person, however, who wishes to know botany as a science, that is, as a body of general truths, can be content with making names his ultimate object. Such a person will be constantly and irresistibly led on to attempt to catch sight of the natural arrangement of plants, even before he discovers, as he will discover by pursuing such a course of study, that the knowledge of the natural arrangement is the knowledge of the essential construction and vital mechanism of plants. He will consider an artificial method as a means of arriving at a natural method. Accordingly, however much some of his followers may have overlooked this, it is what Linnæus himself always held and taught. And though what he executed with regard to this object was but little," the distinct manner in which he presented the relations of an artificial and natural method, may justly be looked upon as one of the great improvements which he introduced into the study of his science. Thus in the Classes Plantarum (1747), he speaks of the difficulty of the task of discovering the natural orders, and of the attempts made by others. "Yet," he adds, "I too have labored at this, have done something, have much still to do, and shall labor at the object as long as I live." He afterwards proposed sixty-seven orders, as the fragments of a natural method, always professing their imperfection." And in others of his works" he lays down some antitheses on the subject after his manner. "The natural orders teach us the nature of plants; the artificial orders enable us to recognize plants. The natural orders, without a key, do not constitute a Method; the Method ought to be available without a master." That extreme difficulty must attend the formation of a Natural Method, may be seen from the very indefinite nature of the Aphorisms upon this subject which Linnæus has delivered, and which the best botanists of succeeding times have assented to. Such are these ;the Natural Orders must be formed by attention, not to one or two, but to all the parts of plants;-the same organs are of great importance in regulating the divisions of one part of the system, and "The natural orders which he proposed are a bare enumeration of genera, and have not been generally followed. 13 Phil. Bot. p. 80. 14 Genera Plantarum, 1764. See Prælect. in Ord. Nat. p. xlviii. of small importance in another part;"-the Character does not constitute the Genus, but the Genus the Character;-the Character is necessary, not to make the Genus, but to recognize it. The vagueness of these maxims is easily seen; the rule of attending to all the parts, implies, that we are to estimate their relative importance, either by physiological considerations (and these again lead to arbitrary rules, as, for instance, the superiority of the function of nutrition to that of reproduction), or by a sort of latent naturalist instinct, which Linnæus in some passages seems to recognize. "The Habit of a plant," he says, "must be secretly consulted. A practised botanist will distinguish, at the first glance, the plants of different quarters of the globe, and yet will be at a loss to tell by what mark he detects them. There is, I know not what look,-sinister, dry, obscure in African plants; superb and elevated, in the Asiatic; smooth and cheerful, in the American; stunted and indurated, in the Alpine." Again, the rule that the same parts are of very different value in different Orders, not only leaves us in want of rules or reasons which may enable us to compare the marks of different Orders, but destroys the systematic completeness of the natural arrangement. If some of the Orders be regulated by the flower and others by the fruit, we may have plants, of which the flower would place them in one Order, and the fruit in another. The answer to this difficulty is the maxim already stated; that no Character makes the Order; and that if a Character do not enable us to recognize the Order, it does not answer its purpose, and ought to be changed for another. This doctrine, that the Character is to be employed as a servant and not as a master, was a stumbling-block in the way of those disciples who looked only for dogmatical and universal rules. One of Linnæus's pupils, Paul Dietrich Giseke, has given us a very lively account of his own perplexity on having this view propounded to him, and of the way in which he struggled with it. He had complained of the want of intelligible grounds, in the collection of natural orders given by Linnæus. Linnæus" wrote in answer, "You ask me for the characters of the Natural Orders: I confess I cannot give them." Such a reply naturally increased Giseke's difficulties. But afterwards, in 1771, he had the good fortune to spend some time at Upsal; and he narrates a conversation which he held with the great 15 Phil. Bot. p. 172. SHOW TH teacher on this subject, and which I think may serve b nature of the difficulty-one by no means easit removed and tax general reader, not even readily comprenende will distress Giseke began by conceiving that at Order must have that attribute from which its name is derived:-tum the Tukiuno mas have ther flower disposed in an umbel. The mighty master smied" and told him not to look at names. but at nature. but all the mil "what is the use of the name, if it does not meat vir professes t ~ WHAT VOL cul mean!" "It is of small import" (replied Limæus the Order, if you take a proper series of piante and giver some nanić. which is clearly understood to apply to the bank vilici you have associated. In such cases as you refer 10. I followed the grea UK, Lai vor of borrowing a name a potior, from the prinema membent. Giecka. (he added) give me the character of ary singe Cruer ” “Surely, the character of the Umbelicio is that they have an umbe Linnæus. “Good: but there are plants which have a umine. and are not of the Umbellata" G. I remember. We must therefort add, that they have two naked seeds." L. The Ecianopora. which has only one seed, and Eryngium, wich has not at umie.. will not be Umbellata; and yet they are of the Order." G. +1 would place Eryngium among the Aggregata." L. No bou are beyond dispute Umbellata. Eryngium has an involucrum. five G. 1 stamina, two pistils, &c. Try again for your Character" would transfer such plants to the end of the Order, and make then form the transition to the next Order. Eryngium would connect the Umbellate with the Aggregata." LA! my good friend the Transition from Order to Order is one thing: the Character of an Order is another. The Transitions I could indicate: but a Character of a Natural Order is impossible. I will not give my reasons for the distribution of Natural Orders which I have published. You or some other person, after twenty or after fifty years, will discover them, and see I was in the right." I have given a portion of this curious conversation in order to show that the attempt to establish Natural Orders leads to convictions which are out of the domain of the systematic grounds on which they profess to proceed. I believe the real state of the case to be that the systematist, in such instances, is guided by an unformed and undeveloped apprehension of physiological functions. The ideas of the form, num 18 "Subrisit & zavı.” ber, and figure of parts are, in some measure, overshadowed and superseded by the rising perception of organic and vital relations; and the philosopher who aims at a Natural Method, while he is endeavoring merely to explore the apartment in which he had placed himself, that of Arrangement, is led beyond it, to a point where another light begins, though dimly, to be seen; he is brought within the influence of the ideas of Organization and Life. The sciences which depend on these ideas will be the subject of our consideration hereafter. But what has been said may perhaps serve to explain the acknowledged and inevitable imperfection of the unphysiological Linnæan attempts towards a natural method. "Artificial Classes are," Linnæus says, a substitute for Natural, till Natural are detected." But we have not yet a Natural Method. "Nor," he says, in the conversation above cited, "can we have a Natural Method; for a Natural Method implies Natural Classes and Orders; and these Orders must have Characters." "And they," he adds in another place," "who, though they cannot obtain a complete Natural Method, arrange plants according to the fragments of such a method, to the rejection of the Artificial, seem to me like persons who pull down a convenient vaulted room, and set about building another, though they cannot turn the vault which is to cover it." How far these considerations deterred other persons from turning their main attention to a natural method, we shall shortly see; but in the mean time, we must complete the history of the Linnæan Reform. Sect. 6.-Reception and Diffusion of the Linnaean Reform. We have already seen that Linnæus received, from his own country, honors and emoluments which mark his reputation as established, as early as 1740; and by his publications, his lectures, and his personal communications, he soon drew round him many disciples, whom he impressed strongly with his own doctrines and methods. It would seem that the sciences of classification tend, at least in modern times more than other sciences, to collect about the chair of the teacher a large body of zealous and obedient pupils; Linnæus and Werner were by far the most powerful heads of schools of any men who appeared in the course of the last century. Perhaps one reason of this is, that in these sciences, consisting of such an enormous multitude of species, of descriptive 19 Gen. Plant. in Prælect. p. xii. |