by their laws, nor does any practical botanist waste his thoughts or judgment in comparing their different merits.

Two systems at the present day divide the botanical world between them, the artificial one of Linnæus, and the natural one of Jussieu. Yet it can be only those who are very unphilosophical or ignorant of the subject, or who have some sinister purpose to serve, who bring these systems into competition as rivals. They are in fact allies and mutual supports, and it is the opinion of an experienced botanist (Dr. Smith) of the present day, that in the actual state of the science perhaps neither of these systems can stand alone. Plants are so numerous, and those of their parts upon which all systems depend so liable to variations and irregularities, that neither the Linnæan system, nor any other artificial one, however simple and comprehensive its principles, can conform to them all with sufficient precision to be in any degree infallible. On the other hand, every natural system is necessarily so incomplete, for want of an uniformly perfect knowledge in its contriver of all the plants in the world, and of their mutual dependencies on each other, as well as of the best possible manner of defining and characterizing the classes and orders in which human contrivance is obliged to dispose them, that to use such a system for the investigation of plants, is like learning to read by the Chinese character. But if we use these two methods in conjunction, they eminently assist each other. If a new plant cannot be made out but by artificial marks, its affinity may be guessed at in the natural system. We shall now proceed to give an outline of both systems, that the student may understand their principles, and comprehend their several advantages.

The Linnæan system is founded on the number, situation, and proportion of the essential organs of impregnation termed stamens and pistils, whose uses and structure we have sufficiently explained. The classes, which are 24, principally owe their distinctions to the stamens; the orders, or subdivisions of the classes, are generally marked by the number of the pistils, or by some other circumstances equally intelligible. The names of both are of Greek derivation, and allude to the functions of the respective organs. The first eleven classes are distin- ' guished solely by the number of the sta

mens.

1. Monandria. Stamen 1. From μovos one,

of grass.

3. Trigynia. Piper only, or pepper.
III. Triandria. Stamens 3.

1. Monogynia. Valeriana, Iris, Cyperus, Scirpus.

2. Digynia. Contains almost all the natural order of true grasses.

3. Trigynia. Holosteum, Montia, Polycarpon..

IV. Tetrandria. Stamens 4. 1. Monogynia. Protea, Scabiosa, Plantago, Galium.

2. Digynia. Buffonia.

3. Tetragynia. Potamogeton, Ruppia. V. Pentandria. Stamens 5. One of the largest classes.

1. Monagynia. Borago, Echium, Primula, and some genera removed hither from the 19th class, to be mentioned hereafter, as Viola, Jasione, &c.

2. Digynia. Chenopodium, Ulmus, Gentiana. Then follow the whole natural order of Umbelliferæ, of which Daucus, Angelica, Cicuta, and Apium, are examples. 3. Trigynia. Viburnum, Sambucus. 4. Tetragynia. Parnassia.

5. Pentagynia. Statice and Linum.
6. Polygynia. Myosurus only.
VI. Hexandria.

Stamens 6.

1. Monogynia. Lilium, and others of its natural order, thence called Liliaceous: a tribe considered by Linnæus as the nobles of the vegetable kingdom; an idea supposed to allude not merely to their beauty and splendour, but also the text, "Consider the lilies of the field how they grow, they toil not, neither do they spin."

2. Digynia. Oryza and Gahnia, grasses with 6 stamens.

3. Trigynia. Rumex, Colchicum, Scheuchzeria, the latter lately discovered to be a British genus, by the Rev. Mr. Dalton, of Yorkshire.

4. Tetragynia. Petiveria only.

5. Hexagynia. Wendlandia and Damasonium of Schreber.

6. Polygynia. Alisma only.

1. Monogynia.

A large and beautiful order, containing Epilobium, Fuchsia, Vaccium, and the vast genus Erica; also, according to Dr. Smith, Acer.

2. Digynia. Mæhringia, &c. 3. Trigynia. Polygonum, &c. 4. Tetragynia. Adoxa, Paris. IX. Enneandria. Stamens 9.

1. Monogynia. Laurus, famous for producing the cinnamon, sassafras, and camphor.

2. Trigynea. Rheum, the rhubarb only. 3. Hexagynia. Butomus.

X. Decandria. Stamens 10. A rather numerous class.

1. Monogynia. Cassia, and some other papilionaceous plants. Also Ruta and its family, followed by Kalmia, Rhododendron, Andromeda, &c.

2. Digynia. Saxifraga, Dianthus, Saponaria.

3. Trigynia. Silene and Arenaria, both allied to Dianthus; also Malpighia and Bannisteria.

4. Pentagynia. Lychnis, Cerastium, and Spergula; allied also to Dianthus. Cotyledon, Sedum, and Oxalis follow.

5. Decagynia. Neurada and Phytolacca. XI. Dodecandria. Stamens 12-19. 1. Monogynia. Lythrum, Halesiæ, Peganum.

2. Digynia. Agrimonia.

3. Trigynia. Reseda and Euphorbia. 4. Tetragynia. Has been recently established to receive Calligonum and Apousgeton.

5. Pentagynia. Glinus. 6. Dodecagynia. houseleek.

Sempervivum, the

Thus far the Linnæan classes are founded solely upon the number of the stamens. In the following ones insertion, proportion, and connection of the same parts are to be considered. Of all the preceding classes the characters of the 4th, 6th, and 10th, chiefly interfere with any of the subsequent ones, as will be explained hereafter.

XII. Icosandria. Stamens twenty or more, inserted into or growing out of the calyx. This mode of insertion always indicates an eatable and wholesome fruit.

1. Monogynia. Myrfus, Amygdalus, Prunus.

2. Pentagynia. According to Dr. Smith should comprise also the Digynia and Trigynia of Linnæus, as they all vary one into the other. Pyrus, Mespilus, Spinæa, and Mesambryanthemum.

3. Polygynia. Rosa, and its beautiful natural order, including Rubus, Fragaria, &c.

XIII. Polyandria. Stamens numerous, inserted into the receptacle. This class is very distinct in character and qualities from the last. Its plants are often poisonous.

1. Monogynia. A fine order. Capparis, Papaver, Nymphæa, Cistus.

2. Pentagynia. Dr. Smith recommends in his "Introduction to Botany," the same plan in this class as in the preceding, of uniting Digynia, Trigynia, Tetragynia, and Hexagynia of Linnæus, under Pentagyiz, because as they stand now in his works, natural genera as well as the species of one genus are often separated, and several plants vary from one Linnæan order to another. Examples are, Pæonia, Delphinium, Aquilegia, Nigella, Stratiotes. Some Nigellæ have ten styles.

3. Polygynia. Dillenia, Magnolia, Anemone. Clematis, Ranunculus, &c. XIV. Didynamia. and two short.

Stamens two long

This class therefore is distinguished from the 4th by the proportion of its filaments, a circumstance which is only an index to other characters in the flower, for there is a correspondent irregularity in the form of the corolla. The class in question is almost perfectly a natural one, containing the Labiate, Ringens, or Personate flowers in general. The orders are as natural as the class, being only two, and founded on the structure of the fruit.

1. Gymnospermia. Seeds naked in the bottom of the calyx, almost always four. The plants are aromatic and wholesome. Some of the principal genera are Teucrium, Mentha, Lavandula, Lamium, Thymus, and Melittis.

2. Angiospermia. Seeds enclosed in a seed-vessel, and generally very numerous. The plants of this order are handsome, but fœted and poisonous, quite distinct in nature from those of the former, and more akin to the Pentandria Monogynia. The genera Bignonia and Antirrhinum sometimes vary with five stamens and regular flowers. Interesting genera of this order are Pedicu

XV. Tetradynamia. Stamens four long and two short. A natural class, comprising the cruciform flowers, except Cleome, which is thought to have been erroneously placed here. The orders are two, perfectly

natural.

1. Siliculosa. Fruit a roundish pod or pouch, Myagrum, Draba, Lunaria, Alysum, Cochlearia, Thlaspi.

2. Siliquosa. Fruit a very long pod, Dentaria, Cardamine, Cheiranthus, Brassica, Sinapis.

XVI. Monadelphia. Stamens united by their filaments into one tube. This is the first class in which the connexion of those parts is taken into consideration. Number therefore being here of secondary importance, serves to discriminate the orders.

1. Triandria. Sisyrinchium, Ferraria, Tamarindus, Aphyteia.

2. Pertandria. Erodium, Hermannia. 3. Heptandria. Pelargonium only, separated from Geranium by L'Herritier, an eminent French botanist.

4. Octandria. Aitonia, named by the younger Linnæus after the late Mr. Aiton of Kew garden.

6. Endecandria. Brownea only.

7. Dodecandria. Stamens generally fifteen. Pterospermum, Pentapetes, &c.

8. Polyandria. The finest order of the whole, contains Malva, Sida, Althæa, Lavatera, Gossypium, Hibiscus, Camellia, and others; most mucilaginous emollient plants.

XVII. Diadelphia. Stamens united by their filaments into two parcels, both sometimes cohering at the base. Flowers almost universally papilionaceous.

1. Pentandria. Monnieria only.
2. Hexandria. Saraca, Fumaria.
3. Octandria. Polygala.

4. Decandria. The largest and most natural order, tho sections of which require to be studied with care.

* Stamens all united. These plants are strictly monadelphous, and it is only on account of their close affinity to the rest of the order that Linnæus took the liberty of placing them here. Some of them indeed, as Lupinus and Ulex, have the tenth stamen unlike the rest, though united with them below. No confusion arises in practice from this seeming contradiction of the character of the class, because the habit of these flowers is so clear and distinct from all others. If, however, a papilionaceous plant

** Stigma downy. Without the character of the foregoing section. Phaseolus, Dolichos, Orobus, Pisum, Lathyrus, Vicia, to which Dr. Smith has added Eroum, after separating from the latter some species erroneously referred to it. See Flora Britannica, 776.

*** Legume imperfectly divided into two cells. Always without the character of the preceding sections. Biserrula, Phaca, Astragalus, the last a very extensive and intricate genus.

**** Legume with scarcely more than one seed. Psoralia, Trifolium, the latter a very irregular genus in character, though distinct in habit, sufficiently known for its agricultural uses.

***** Legume composed of single-valved joints which are rarely solitary. Hedysarum, Hippocrepis, Coronilla, Smithia, the latter furnished with irritable leaves like the true Sensitive plant or Mimosa.

****** Legume of one cell with several seeds. Many species of Trifolium properly belong here, and have been separated by some authors under the name of Melilotus; also the valuable Indigofera, with Cytisus, Robinia, Lotus, and Medicago.

XVIII. Polyadelphia. Stamens united by their filaments into more than two parcels. Orders characterized by the number or insertion of their stamens. In this class Dr. Smith has made many corrections, and the orders in his Introduction to Botany stand as follows.

1. Dodecandria. Stamens, or rather an thers, from twelve to twenty or twenty-five. Their filaments unconnected with the calyx. Theobroma, the chocolate tree, Bubroma, Abroma, Monsonia, and Citrus.

2. Icosandria. Stamens numerous, their filaments inserted into the calyx, in several parcels of course, as Melaleuca, a fine aromatic genus, principally from New Holland. 3. Polyandria. Stamens very numerous, unconnected with the calyx. Hypericum is the principal genus here.

XIX. Syngenesia. Anthers united into a tube, Flowers compound. This is entirely a natural class, and its orders likewise are founded on natural characters.

1. Polygamia Æquales. Every one of the florets which constitute the compound flower is, in this order, perfect within itself, having perfect stamens and pistil with one seed. The florets are either ligulate, as in

.

the dandelion; tubular, forming a globose head, as in the thistle; or tubular, and level at the top; or discoid, as in lavender cotton, santolina.

2. Polygamia Superflua. Florets of the disk like the discoid, flowers of the last order, and, like them, perfect within themselves. Those of the margin furnished with pistils only, but all the florets produce perfect seed. In this order the marginal florets are sometimes minute and inconspicuous, but they are for the most part ligulate, and from diverging rays, as in the daisy, aster, chrysanthemum, &c.

3. Polygamia Frustranea. Differs from the last order only in having the florets of the margin abortive or neuter; in the former case there are no rudiments of a pistil in these florets, as in centaurea; or there are abortive pistils, as in the sun-flower. This order is considered by Dr. Smith as not essentially different from the last.

4. Polygamia necessaria. Florets of the disk furnished with perfect stamens only, those of the margin with perfect pistils only, as in the garden marigold, calendula.

5. Polygamia Segregata. Several flowers, either simple or compound, with united anthers, and a partial calyx, all included in one general calyx, as the globe thistle, &c.

Another order follows in Linnæus, called Monogamia, consisting of simple. flowers with united anthers; but this order is now generally abolished. The circumstance of the union of the anthers in simple flowers being extremely various and uncertain, though in compound ones scarcely liable to any exception.

XX. Gynandria. Stamens inserted either upon the style or germen. Such is the true idea of this class, and its character thus understood is as much founded in nature and reality as that of any other; by which we do not mean, that the class is a natural one, like the 19th, as it, in fact, comprises several natural families, whose allies may happen to be in other classes. Linnæus, in his idea of this class, has understood as belonging to it, many plants whose stamens did not really grow out of the germen, as the passionflower, the sisyrinchium, &c. Hence Thunberg, and some other botanists, have judged the class altogether untenable. In the orders some alterations have recently been made by Dr. Smith, the reasons for which are more fully particularized in his Introduction to Botany, than we haye room here to explain. These orders are distinguished by the number of stamens. Monandria,

the first of them, contains almost all the Orchis tribe. To the fifth, Pentandria, Dr. Smith refers many of the natural family of Contortæ, as Pergularia, Cynanchum and Asclepias, a curious tribe, the structure of whose organs of impregnation is extremely puzzling even to the botanical adept. They have hitherto been placed in the fifth class, and some have thought they should be referred to the tenth. In the 6th order of this class, Hexandria, we find the aristolochia, or birth-wort.

XXI. Monoecia. Stamens and pistils in separate flowers, but on the same plant.

The orders of this class are, like those of the last, distinguished by the number of the stamens, or by some other character of the foregoing classes. The most genuine examples of it are such as have a different structure in the two kinds of flowers, besides the essential difference with respect to stamens and pistils, as the oak, chesnut, hazle.

XXII. Dioecia. Stamens and pistils like the former in separate flowers, but on two separate plants.

The orders of this class are characterised like those of the preceding. The willow, hop, hemp, &c. belong to it.

XIII, Polygamia. Stamens and pistils separate in some flowers, united in others, either on one, two, or three distinct plants, Dr. Smith has first suggested that no plants should be admitted into this class without a difference in the accessory parts of their flowers, over and above what concerns the stamens and the pistils. Without such a rule the class would be overwhelmed with the trees of tropical countries.

The orders are Monoecia, when the several kinds of flowers grow on one plant, as Atri plex: Dioecia, when they are situated on two separate ones; and Trioecia, when they occupy three several individuals of the same species,

XXIV. Cryptogamia, Stamens and pistils either not well ascertained, or not to be numbered with certainty,

1, Filices, ferns, whose flowers are almost entirely unknown. The seed-vessels commonly grow on the back of the leaf, thence denominated a frond, and are either naked or covered with a membrane. In some few they form spikes or clusters of capsules.

2, Musci, mosses, a peculiar family of plants, possessing great elegance, though diminutive in size; extremely tenacious of life, growing in the hottest as well as the coldest climates; flourishing most in the

damp wintry months. Their herbage consists of pellucid leaves, sometimes accompanied with a stem; their capsule is of one cell and of one valve, closed with a vertical lid; seeds numerous and small; the capsule is covered with a calyptra or membranous veil, the summit of which is the stigma, a circumstance absolutely peculiar to this family; the stamens are mostly in a separate flower and numerous. The late Dr. Hedwig of Leipsic is celebrated for his discoveries relating to mosses. He has distinguished their genera by the peristomium or fringe, which in most cases surrounds the mouth of the capsule. This fringe is either single or double. In the former case it consists of either four, eight, sixteen, thirtytwo, or sixty-four teeth. The inner peristomium when present is more membranous, plaited, and jagged. The principles of Hedwig have been adopted with a few requisite limitations by the most able writers in this branch of botany.

3. Hepatica, liverworts. The herbage of these plants is most generally a frond, or leaf, bearing the fructification; but they differ most essentially from the last order in the want of a lid to the capsule, which is formed quite on a different principle from that of mosses, and very various in the several genera. Jungermannia and Marchantia are examples of this order.

4. Alga, flags. The herbage of these is also frondose, being sometimes a powdery crust, sometimes leathery or gelatinous; the seeds are imbedded in the frond, or in some appropriate receptacle; the stamens are scarcely known. The vast family of Lichen occurs here, the most hardy of vegetables, clothing exposed rocks, trunks of trees, and barren heaths, in the most cold and inhospitable climates. On one of them the rein-deer depends for sustenance in the winter. Others are useful in dyeing, and even medicine. The numerous and various tribe of sea-weeds, Fucus, Conferva, and Ulva, are classed here.

5. Fungi, mushrooms. These are fleshy in substance, of quick growth, and generally of short duration. They are divided into Angiocarpi which bear seeds internally; and Gymnocarpi, whose seeds are imbedded in an exposed membranous organ. Many of these are eatable, some poisonous. Linnæus had a great prejudice against the use of any of them as food.

APPENDIX. Palma. The magnificent. natural order of palms was placed by Lin. næus as an appendix to his system, because

their parts of fructification were not well known when he first wrote. They are now, however, in general so well understood that the plants in question are easily reducible to the regular classes of the Linnæan system; and it would be advisable for any future editor to arrange them accordingly. They principally belong to the Hexandria Monogynia, and are nearly allied to many plants already referred to that class.

Palms are called by Linnæus the princes of the vegetable kingdom, and are remarkable for their lofty growth, their simple stems crowned with evergreen leaves, and their abundant fruits. Among them we find the date, so valuable an article of food for many nations; the cocoa-nut, and many other fruits of less value. Some supply whole nations with oil, for food or economical uses, from their fruits, with wine from the juices of their stem, or with cordage from its fibres.

We shall now proceed to give a sketch of the natural system of arrangement published by Jussieu, a botanist of the first eminence, now living at Paris. Its primary divisions are founded upon the structure of the seed, whence is derived the distinction of all plants into Acotyledones, destitute of a cotyledon; Monocotyledones, such as have one cotyledon; and Dicotyledones, such as have two. Under the last are included a few genera that have numerous cotyledons, as Pinus and its allies, which Jussieu considers as having two cotyledons, each divided into several segments, but erroneously. So that this last section should rather be characterized as having two or more cotyledons.

The classes of Jussieu's method are fifteen, and comprize in all an hundred orders. These classes have no appropriate names, but are distinguished by numbers with a short definition of the essential character. The orders, except those of the first class, are for the most part named after some principal genus belonging to each. It is to be observed that with respect to the cotyledons, there are some inaccuracies in the terms used, for many of the supposed Monocotyledones are now known to have no cotyledon at all, and what has been so called in the rest is more properly an albumen.

Class I. Acotyledones. The orders of this are in a great measure analogous to the 24th class in Linnæus. 1. Fungi; 2. Algæ; 3. Hepatica; 4. Musci; 5. Filices; to which is added a sixth, termed Naiades, which