them, to render their distinctions nugatory, and by another, clear and precise. Now, if the supposed groups are really as closely allied, as for this argument we may assume them to be, it can be of no possible importance theoretically, whether a given Genus or Order is placed in the one or the other. The near consanguinity of the two does away with all importance in such a case. In Physical Geography it is of no consequence whether London is stationed in Middlesex or Surrey; and in like manner, in Theoretical Botany, the place of a given Order may be equally indifferent. But it may be of great consequence practically, because a definition of limits may be possible or not, according to the arrangement. For example, let us take the Solanal and Bignonial Alliances. These touch at the Orders of Nightshades and Figworts respectively. If Nightshades are placed in the Bignonial Alliance because of their intimate relation to Figworts, no apparent means remain of clearly defining what is meant by the Bignonial Alliance. If, on the other hand, Figworts are stationed in the Solanal Alliance, then the distinctive characters of that Alliance are also rendered obscure and difficult, or impossible of application. But place Nightshades in the Solanal, and Figworts in the Bignonial Alliance, and the language of Botanists affords as clear a discrimination as can be wished for. And so of other cases. Indeed, I am so persuaded of this, that in my opinion all instances of confused and vague characters are only so many proofs of Botanists not having clearly understood the plants that they have endeavoured to classify.* It will, perhaps, be alleged that the doctrine just inculcated is directly opposed to the first principles of a Natural System: but such is not the case. No absolute limits, in fact, exist, by which groups of plants can be circumscribed. They pass into each other by insensible gradations, and every group has apparently some species which assumes in part the structure of some other group. Two countries are separated by a river whose waters are common to both banks: in a geographical division of territory the river may be assigned to either the left bank or the right bank, but such an arrangement is arbitrary; and yet the interior of the countries is unaffected by it. So with the groups of plants; it cannot be of any possible consequence whether an intermediate or frontier plant be assigned to one group or another, and convenience alone should be considered in such a matter. This long since led me to offer the following observations, the justice of which, much more experience entirely confirms :-"All the groups into which plants are thrown are in one sense artificial, inasmuch as Nature recognises no such groups. Nevertheless, consisting in all cases of species very closely allied in nature, they are in another sense natural. as the Classes, Sub-classes, Alliances, Natural Orders, and Genera of Botanists, have no real existence in nature, it follows that they have no fixed limits, and consequently that it is impossible to define them. They are to be considered as nothing more than the expression of particular tendencies (nixus), on the part of the plants they comprehend, to assume a particular mode of development. Their characters are only a declaration of their prevailing tendencies." But We must not, however, deceive ourselves with the expectation that by this or any other expedient definitions in Botany will become possible. Mathematical precision is unknown in such subjects, and exceptions occur • No Botanist will regard this as an offensive remark. It is the misfortune, not the fault, of men of science, that they cannot investigate everything with their own eyes, and that they are compelled, from the vastness of their subject, to take much of all they study upon trust. In Botany this is most especially the case; for who has ever been able to examine one-tenth of all the plants he speaks of, with minute accuracy? to all known rules. "When Zoology," says Mr. Milne Edwards, "is only studied in systematic works, it is often supposed that each class, each family, and each genus, present to us boundaries precisely defined, and that there can be no uncertainty as to the place to be assigned, in a natural classification, to every animal the organisation of which is sufficiently known. But when we study this science from Nature herself, we are soon convinced of the contrary, and we sometimes see the transition from one plan of structure to an entirely different scheme of organisation take place by degrees so completely shaded one into the other that it becomes very difficult to trace the line of demarcation between the groups thus connected."—Ann. Sc. Nat. 1840, Sept. Ray long ago pointed this out in a very remarkable passage, which cannot be too often quoted. Nec Verum quod alias dixi illud hic repeto et inculco, non sperandam à me Methodum undequaque perfectam et omnibus suis numeris absolutam, quæ et plantas in genera ità distribuat ut universæ species comprehendantur, nulla adhuc anomalâ et sui generis reliquâ, et unumquodque genus notis suis propriis et characteristicis ità circumscribat, ut nullæ inveniantur species incerti, ut ita dicam, laris, et ad plura genera revocabiles. enim id patitur natura rei. Nam, cùm Natura (ut dici solet) non faciat saltus, neque ab extremo ad extremum transeat nisi per medium, inter superiores et inferiores, rerum ordines nonnullas mediæ et ambiguæ conditionis producere solet, quæ de utroque participent, et utrosque velut conPræterea eadem nectant, ut ad utrum pertineant omninò incertum sit. alma parens in methodi cujuscunque angustias coerceri repugnat, sed ad libertatem et avтovoμíav suam nullis legibus obnoxiam ostentandam, in unoquoque rerum ordine nonnullas species creare solet, tanquam exceptiones à regulis generalibus, singulares et anomalas."-(RAII, Hist. Plant. vol. i. Præf.) Linnæus did but copy this when he asserted that Nature makes no leaps (Natura non facit saltus.-Phil. Bot. 77.) This doctrine has, however, been lately called in question by no less eminent a writer than M. Alphonse De Candolle, who requires that absolute limits should be assigned to all groups of whatever degree. "If," he says, "we cannot state in what respect two families differ permanently and universally, those two families are but one. Two pieces of land which touch each other form one island, and not two; but two pieces of land which are separated by an arm of the sea, form two islands, and not one." 254. p. -Annales des Sciences, series 3, vol. 1. But this is a kind of reasoning wholly inapplicable to Natural History, for the reasons so adIf the groups mirably given by Ray, and is contrary to all experience. limited by M. Alphonse De Candolle himself are examined by this standard they alone suffice to demonstrate how visionary are such expectations. Mr. Bentham has satisfactorily answered the learned Botanist of Geneva. "We Botanists," he says, "cannot be so mathematically exact as geographers, and where an isthmus is very narrow, we must class the peninsula with the island. How often does it happen that two large Orders, say of five hundred to two thousand or three thousand species, totally distinct from each other in all those species by a series of constant characters, are yet connected by some small isolated genus of a dozen, half a dozen, nay a single species, in which these very characters are so inconstant, uncertain, or variously combined as to leave no room for the strait through which we ought to navigate between the two islands."-London Journal of Botany, 4. 232. It would be very convenient to find that the views of M. Alphonse De Candolle were practicable, but in truth they are quite Utopian. While, however, the impracticability of absolute definitions is thus insisted upon, there can be no doubt that much more precision may be introduced than is too frequently found among them. Exceptions, although to some extent inevitable, are not uncommonly apparent, not real. It will frequently be found that a particular species is at variance with the definition of its Genus, or of a Genus with that of its Order, or of an Order with that of its Alliance; but, upon a full examination of all the structure of such supposed exceptions, it will turn out that they are misplaced, and do not in fact belong to the station which they occupy. Exceptions of this kind were formerly very common, but they are disappearing under the diligent criticism of modern observers. The genus Rhynchotheca may be taken as an example. The great feature of the Cranesbills is their beaked torus and folded-up embryo, and it is by that circumstance that they are essentially distinguished from their neighbours. But Rhynchotheca was described as having a beaked fruit and straight embryo; it therefore formed an apparent exception to the definition of Cranesbills. Investigation of the plant has however shown that its beak belongs to the carpels and not to the torus; and, therefore, it is merely an Oxalid, with a tendency towards the structure of a Cranesbill. The manner in which the foregoing principles have been applied to practice has differed greatly, and the result has been schemes of various degrees of merit, some of which have dropped still-born from the press, while others continue to enjoy a well-deserved reputation. It would be alike unjust to their authors and the public to omit all mention of even the most obscure of these, each of which has been the result of much thought and patient study, and has doubtless contributed something to the progress of systematic science. But it would be beyond the object of the present sketch to treat them all at length, nor would the student derive any advantage from doing so. While, therefore, the following pages will be occupied by some account of every plan for a Natural classification of which I have any knowledge, since the year 1789 inclusive, and of those of Ray and Linnæus of an earlier date, such as are comparatively unimportant will be dismissed in a few words, and those only which have been really employed in practice will be stated at length. In order to render the latter more useful, references are given to the pages in the present work where an account of each Order may be found; so that those who are accustomed to the use of other systems may not experience inconvenience from the arrangement proposed in the work now submitted to their consideration. *I do not, however, include the arrangements of the German Naturphilosophists; not, indeed, from any disrespect to those learned men, but because I must confess my inability to master their ideas, or to comprehend how their views are made applicable to any intelligible classification. The student will, I believe, find full information upon the subject in Oken's Lehrbuch der Naturphilosophie, edition of 1843. See also Reichenbach's Conspectus Regni Vegetabilis, 1828, the same author's Flora Germanica Excursoria, 1830-2, and Schultz Futurliches System des Pflanzenreichs, 1832. NATURAL SYSTEMS. [Where references are given after the names of Orders, in this part of the present work, they refer to the page where such Orders are to be found in the succeeding sheets). 1703. RAY, John.-(Methodus Plantarum emendata et aucta). Here we have the germ of the present methods of natural arrangement. In fact the first divisions of the Vegetable Kingdom, proposed by Ray, are identical with those of Jussieu. Like him, he proceeded from the more imperfect to the most highly organised forms; the only difference being that he placed Dicotyledons before Monocotyledons. The author's words are " Floriferas dividemus in dicotyledones, quarum semina sata binis foliis anomalis, seminalibus dictis, quæ cotyledonum usum præstant, è terrâ exeunt, vel in binos saltem lobos dividuntur, quamvis eos supra terram foliorum specie non efferant ; et monocotyledones que nec folia seminalia bina efferunt nec lobos binos condunt. Hæc divisio ad arbores etiam extendi potest: siquidem palmæ et congeneres hoc respectu eodem modo a reliquis arboribus differunt quo monocotyledones à reliquis herbis." His plan was this: Plants are either Flowerless, or Flowering; and these are Dicotyledones, or Among the genera of Ray, which were what we now call Natural Orders, were Fungi, Mosses, Ferns, Composites, Cichoraceae, Umbellifers, Papilionaceous plants, Conifers, Labiates, &c., under other names, but with limits not very different from those now assigned to them. 44 1751. LINNAEUS, Charles.-(Philosophia Botanica). ** Plantæ omnes utrinque affinitatem monstrant, uti Territorium in mappa geographica." The following is the Natural distribution first proposed by Linnæus, under the name of Fragments. Many of his groups were taken from his predecessors; others were contrived by himself. At a later period they underwent some alteration; but the list now given will serve to show the learned author's plan. He never assigned any characters to these Fragments. 1. PIPERITE. Arum, &c. Piper, Phytolacca. 2. PALME, Corypha, &c., Cycas. 3. SCITAMINA. Musa, Canna, Amomum, &c. 4. ORCHIDEE. As now. 5. ENSATE. Iris, &c., Xyris, Eriocaulon, Aphyl lanthes. 6. TRIPETALOIDEE. Butomus, Alisma, Sagittaria. 7. DENUDATE. Crocus, &c. 8. SPATHACEE. Leucoium, Amaryllis, &c. 9. CORONARLE. Ornithogalum, Scilla, &c. 10. LILIACEA. Lilium, Tulipa, &c. 11. MURICATE. Bromelia, &c. 12. COADUNATE. Anona, Magnolia, &c., Thea. 13. CALAMARIE. Scirpus, &c., Juncus ? 14. GRAMINA. As now. 15. CONIFERE. Abies, Pinus, &c. 24. BICORNES. Azalea, Myrsine, Memecylon, Santalum, &c. 25. SEPIARI. Jasminum, Ligustrum, Brunfelsia, &c. 26. CULMINE. Tilia, Bixa, Dillenia, Clusia, &c. 27. VAGINALES. Polygonum, Laurus, &c. 28. CORYDALES. Melianthus, Epimedium, Fumaria, Monotropa? &c. 29. CONTORTI. Rauwolfia, Vinca, Asclepias, &c. 32. CAMPANACEL. Convolvulus, Lobelia, Viola, 33. LURIDE. Solanum, &c., Celsia, Digitalis. 16. AMENTACEE. Pistacia, Alnus, Populus, Jug- 35. SENTICOSE. Roseworts exclusively. 17. NUCAM «NTACEE. Xanthium, Iva, &c. 36. COMOSE. Spiræa, Filipendula, Aruncus. 37. POMACE E. Punica, Pyrus, &c., Ribes. 18. AGGREGATE. Statice, Protea, Hebenstreitia, 38. DRUPACEE. As now. Brunia, Valeriana, Boerhaavia, Circa? &c. 39. ARBUSTIVA. Philadelphus, and Myrtleblooms. Enothera, &c., Lythrum, 19. DUMOSÆ. Viburnum, Rondeletia, Cassine, 40. CALYCANTHEME. Rhus, Ilex, Callicarpa, Lawsonia, &c. 20. SCABRIDE. Ficus, &c. 21. COMPOSITE. As now, nearly. 22 UMBELLATE. As now. 23. MULTISILIQUE. Modern Crowfoots. Glaux, Rhexia. 41. HESPERIDE.E. Citrus, Styrax, Garcinia. 43. ASPERIFOLIE. The modern Borageworts. 44. STELLATE. Galium, &c., Hedyotis, Spigelia, 57: SILIQUOSA. Crucifers. Cornus? Coffea, &c. 45. CUCURBITACEA. Passiflora and Cucurbits. 58. VERTICILLATE. Labiates. 59. PERSONATE. Figworts, Sesamum, Justicia, Bignonia, Verbena, &c. 60. PERFORATE. Hypericum, Cistus, Telephium. 47. TRICOCCA. Cambogia, Euphorbia, &c., Cliffor- 61. STATUMINATE. Ulmus, Celtis, Bosea. tia, Sterculia, &c. 62. CANDELARES. Rhizophora, Mimusops, Nyssa. 48. INUNDATÆ. Hippuris, Elatine, Ruppia, Ty- 63. CYMOSÆ. Lonicera, Loranthus, Ixora, Cinpha, &c. chona? &c. 49. SARMENTACEE. Vitis, Hedera, Houstonia, 64. FILICES. As now. Ruscus, Smilax, Menispermum, Aristolochia, 65. Musci. &c. As now. 66. ALGE. Nearly as now. 50. TRIHILATE. Sapindus, Malpighia, Begonia, 67. FUNGI. 51. PRECIE. Part of modern Primworts. &c. 53. HOLERACEA.-Spinacia, &c., Herniaria, Callitriche, Petiveria, &c. 54. VEPRECULE. Rhamnus, &c., Lycium, Daphne, &c. 55. PAPILIONACEAE. As now. All his doubtful genera. At a later period Nos. 7, 10, 11, 17, 26, 27, 36, 38, 39, 60, 61, 62 and 63, were cancelled; and four added, viz. GRUINALES. Cranesbills. Hippophäe, 56. LOMENTACE. Leguminous plants, with IEDERACE. Hedera and Vitis, &c. jointed pods, Caesalpinie and Mimoseæ. MISCELLANEД. A curious mixture. 1789. JUSSIEU, Antoine Laurent de.-(Genera Plantarum secundum ordines naturales disposita, juxta methodum in horto regio Parisiensi exaratum, anno MDCCLXXIV). Adopting the views of Ray as to primary divisions, Jussieu applied them to the system of Tournefort, which had been in common use in France from the year 1694, and which was by far the best suited for the state of knowledge of the age in which it was promulgated. To this he added the position of the stamens with respect to the ovary, and thus constructed his 15 classes in the following manner : Under each of these classes he arranged his Natural Orders as follows, usually deriving their name from some genus, which he regarded as a good illustration of their general structure. |