'descriptive phrase,' or, as it is termed in the language of the Aristotelian logicians, the 'differentia,' are, for the most part, results of the general rule, that the most fixed characters which can be found are to be used; this rule being interpreted according to all the knowledge of plants which had then been acquired. The language of the rules was, of course, to be regulated by the terminology, of which we have already spoken.

9

Thus, in the Critica Botanica, the name of a plant is considered as consisting of a generic word and a specific phrase; and these are, he says, the right and left hands of the plant. But he then speaks of another kind of name; the trivial name, which is opposed to the scientific. Such names were, he says, those of his predecessors, and especially of the most ancient of them. Hitherto 10 no rules had been given for their use. He manifestly, at this period, has small regard for them. Yet,' he says, trivial names may, perhaps, be used on this account,-that the differentia often turns out too long to be convenient in common use, and may require change as new species are discovered. However,' he continues, 'in this work we set such names aside altogether, and attend only to the differentiæ.'

Even in the Species Plantarum, the work which gave general currency to these trivial names, he does not seem to have yet dared to propose so great a novelty. They only stand in the margin of the work. I have placed them there,' he says in his Preface, 'that, without circumlocution, we may call every herb by a single name; I have done this without selection, which would require more time. And I beseech all sane botanists to avoid most religiously ever proposing a trivial name without a sufficient specific distinction, lest the science should fall into its former barbarism.'

It cannot be doubted, that the general reception of these trivial names of Linnæus, as the current language among botanists, was due, in a very great degree, to the knowledge, care, and skill with which

8 Phil. Bot. 266.

9 Ib. 261.

10 Ib. 260.

his characters, both of genera and of species, were constructed. The rigorous rules of selection and expression which are proposed in the Fundamenta Botanica and Critica Botanica, he himself conformed to; and this scrupulosity was employed upon the results of immense labour. In order that I might make myself acquainted with the species of plants,' he says, in the preface to his work upon them, 'I have explored the Alps of Lapland, the whole of Sweden, a part of Norway, Denmark, Germany, Belgium, England, France: I have examined the Botanical Gardens of Paris, Oxford, Chelsea, Harlecamp, Leyden, Utrecht, Amsterdam, Upsal, and others: I have turned over the Herbals of Burser, Hermann, Clifford, Burmann, Oldenland, Gronovius, Royer, Sloane, Sherard, Bobart, Miller, Tournefort, Vaillant, Jussieu, Surien, Beck, Brown, &c.: my dear disciples have gone to distant lands, and sent me plants from thence; Kerlen to Canada, Hasselquist to Egypt, Asbech to China, Toren to Surat, Solander to England, Alstromer to Southern Europe, Martin to Spitzbergen, Pontin to Malabar, Kohler to Italy, Forskähl to the East, Lofling to Spain, Montin to Lapland: my botanical friends have sent me many seeds and dried plants from various countries: Lagerström many from the East Indies; Gronovius most of the Virginian; Gmelin all the Siberian; Burmann those of the Cape.' And in consistency with this habit of immense collection of materials, is his maxim,11 that a person is a better botanist in proportion as he knows more species.' It will easily be seen that this maxim, like Newton's declaration that discovery requires patient thought alone, refers only to the exertions of which the man of genius is conscious; and leaves out of sight his peculiar endowments, which he does not see because they are part of his power of vision. With the taste for symmetry which dictated the Critica Botanica, and the talent for classification which appear in the Genera Plantarum, and the Systema Natura, a person must undoubtedly rise to higher.

11 Phil. Bot. 259.

steps of classificatory knowledge and skill, as he became. acquainted with a greater number of facts.

The acknowledged superiority of Linnæus in the knowledge of the matter of his science, induced other persons to defer to him in what concerned its form; especially when his precepts were, for the most part, recommended strongly both by convenience and elegance. The trivial names of the Species Plantarum were generally received; and though some of the details may have been altered, the immense advantage of the scheme ensures its permanence.

Sect. 4.-Linnæus's Artificial System.

WE have already seen, that, from the time of Cæsalpinus, botanists had been endeavouring to frame a systematic arrangement of plants. All such arrangements were necessarily both artificial and natural: they were artificial, inasmuch as they depended upon assumed principles, the number, form, and position of certain parts, by the application of which the whole vegetable kingdom was imperatively subdivided; they were natural, inasmuch as the justification of this division was, that it brought together those plants which were naturally related. No system of arrangement, for instance, would have been tolerated which, in a great proportion of cases, separated into distant parts of the plan the different species of the same genus. As far as the main body of the genera, at least, all systems are natural.

But beginning from this line, we may construct our systems with two opposite purposes, according as we endeavour to carry our assumed principle of division rigorously and consistently through the system, or as we wish to associate natural families of a wider kind than genera. The former propensity leads to an artificial, the latter to a natural method. Each is a System of Plants; but in the first, the emphasis is thrown on the former word of the title, in the other, on the latter.

The strongest recommendation of an artificial sys

tem, (besides its approaching to a natural method,) is, that it shall be capable of easy use; for which purpose, the facts on which it depends must be apparent in their relations, and universal in their occurrence. The system of Linnæus, founded upon the number, position, and other circumstances of the stamina and pistils, the reproductive organs of the plants, possessed this merit in an eminent degree, as far as these characters are concerned; that is, as far as the classes and orders. In its further subdivision into genera, its superiority was mainly due to the exact observation and description, which we have already had to notice as talents which Linnæus peculiarly possessed.

The Linnæan system of plants was more definite than that of Tournefort, 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 names 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