CLASS IS.
97. Cucurbitacee agree; in name as well as idea, with the 34th of the Linnman orders.
99. Atnentaceee are mostly what Linnaeus has, un der the same appellation, in his 50th order..
As Linnaeus enumerates, at the end of his Natural Orders, 116 genera, which he could not then satisfac torily refer to any one of them; so Jussieu, at the con clusion of his System, reckons up 137, which, as we have already observed, he denominates Planter incertee :edit. These are disposed 'synoptically, by their pe tals, germens and styles. It is remarkable how near ly, allowing for new discoveries, Jussieu accords with Linnaeus in the number of such genera. These lists have both been greatly diminished by subsequent con. sideration, or more complete information.
The attention of botanists, first directed by Gartner, to the minute and curious diversitiel of structure in the parts of the seed, has greatly assisted Jussieu and his followers in correcting and improving the details of his system. Hence he has been led to favour the world with several essays on particular families, or orders, in the Amides du Museum "Hist. Nat., some of which have appeared in the very valuable Annals of Botany, published by Dr Sims and Mr Konig. In these, several of the difficulties, which originally em barrassed their author, are lessened or,removed, but on these it is not our purpose to enter. A new edition of Jussieu's Genera Plantarum, which has long been pre paring, cannot fail to prove almost a new work ; more valuable perhaps for the abundant information which it must afford, concerning the characters and affinities of particular genera, than for any thing concerning a general natural system, to perfect which the scientific world has not, as yet, sufficient materials.
As we cannot here undertake to detail Jussieu's own corrections or improvements of his system, neither min we explain what has been attempted, with the same design, by the late ingenious M. Ventenat, or by those excellent living botanists, M. De Candolle, or Mr Brown. . We shall only observe, that Ventenat, too servile to Jussien, explicitly contends for the na tural method of classification, as superseding the arti ficial one, and that he aims at proving this to have been the intention of Linnaeus. Yet nothing can be more positive to the contrary than the remarks of the latter, in the preface to his Ordines Naturaki at the end of his Genera Plantarusn. He there declares that his " artificial is alone of use to ascertain plants, it being scarcely possible to find a key to the natural one." " Natural orders," he continues, " serve to teach the nature of plants, artificial ones to distin guish one plant from another." If it be said that Jus. Bo*
sieu, having invented a key, or a set of distinctive characters, to his orders, has removed this objection, we would ask, What becomes of his doubtful genera, ea numerous as those of Linnaeus ? or moreover, How is any student, using , his system analytically, to make out a single unknown plant ? That the pupils of ins. sieu have ever been aware of this, the writer of the present essay very well knows. He has always found them, in conversation, liming compliments at their illustrious master, by contending for the great dace!. ty and uncertainty of the Linnman artificial system ; by which palpable absurdity they betrayed their se. cret opinion of Justdeu's. On the other hand, the in telligent and candid De Candolle, adopting the just opinion of Linneus, that plants are allied to each other rather in the form of a table, or map, than in a linear series, actually proposes such a series as neap sarily art*ial, in his Theorie Elementaire de Bola. fugue, 213. Concerning the precise disposition of the genera in this series, we believe scarcely two botanists, would agree ; nor might their contentions be unpro. &table ; but they would never teach, either a tyro or an adept, to ascertain an unknown plant. We will venture to go further, and to declare our opinion, founded on long observation, that botanists who are thus perpetually intent on the abstract theory of clas. sification, scarcely attain any excellence in the tech nical discrimination, or definition, of what are really founded in nature, the species or genera of the vege• table kingdom. Those err greatly who seek to im prove the system of Jussieu, or any other, by refining too much on his distinctions, and subdividing his or ders; than which nothing is more easy. Judgment and extensive knowledge' are displayed in tracing oat i the .most essential points of agreement in natural ote jects ; not in exalting into unmerited importance the most. minute differences. Hence the very conciseness of Linnet's, gives perspicuity to his descriptions and definitions. These afford the most instructive study, whatever mode of classification we may think most con. venient.
The French school has been much flattered, by our able.countryman Mr Brown, having classed his Pro. drowns of the New Holland plants after the method of Jussieu ; and many a botanist enjoys this national triumph who is certainly not competent to appreciate the merit of that work: The plants of so novel a country could not, at this time of day, have been pre sented, with so much advantage, to a philosophical botanist, as in some natural arrangement, however im perfect ; nor many students travel thither, to make them out by methodical investigation. The touchstone of our learned friend's book however will be the Plante incerta wdis, nor can it be judged, at • to the merit of the system employed, till it arrives at that conclusion. He himself will surely not reckon it complete without a Linnman index,