IV. THE NATURAL SYSTEM OF DE CANDOLLE.

MANY natural systems have been proposed by different botanists. Ray, Linnæus, Jussieu, De Candolle, Bartling, Reichenbach, Schultz, Endlicher, myself, and many others, have each had their own system; and, perhaps, the best character that can be given of them is, that while they are all far from the truth, each has some merits which the others want.

The system of De Candolle, however, having been taken as the basis of the most perfect enumeration of plants that has ever been made, has so great a reputation, that for the convenience of students it most requires explanation. And it seems the more deserving of illustration, because the University of London have declared that their examinations shall be conducted with reference to it.

It will not be necessary to introduce into an illustration of this system every natural order; for many are imperfectly known, and only interest the botanist when he extends his inquiries into the minutiae of the science. All, however, of importance, will be found in the succeeding pages.

Plants are either furnished with visible flowers, or they are multiplied in some other way. Hence the two great divisions, of FLOWERING (Phanogamous or Phanerogamous), and FLOWERLESS (Cryptogamous).

Flowering plants are either EXOGENS (95) or ENDOGENS (95), with which Dicotyledons (573) and Monocotyledons (572) respectively correspond.

Flowerless plants are either ÆTHEOGAMOUS (Semivascular), that is, furnished with stomates and vascular tissue; or they are AMPHIGAMOUS (Cellular), that is, destitute of stomates and entirely cellular.

Hence arise four CLASSES.

I. FLOWERING PLANTS.

Class 1. Exogens or Dicotyledons.
Class 2. Endogens or Monocotyledons.

This is the largest class in the vegetable kingdom, comprehending more species than all the others put together. The subclasses are the following:

1. Thalamiflora. A calyx and corolla. Stamens hypogynous.

2.* Calyciflora. A calyx and corolla. Stamens perigynous.

3. Corolliflora. A calyx and corolla. bearing the stamens.

Petals distinct;

Petals distinct;

4. Monochlamydea. A calyx only, or none.

Petals united,

SUBCLASS I. THALAMIFLORE.

Order 1.-Ranunculacea. Herbs or shrubs, occasionally climbing. Leaves with the petiole generally dilated, and the blade very often palmate or digitate. Sepals 3-6, usually deciduous. Petals 3-15, or none. Stamens indefinite; anthers adnate. Carpels numerous, or united into a single pistil. Seeds either erect or pendulous.

USES.-Generally acrid, bitter, narcotic plants, with vesicating leaves, as Aconite, Stavesacre, Crowfoot. Some however have the bitter principle predominant and the acridity slight, as Hydrastis canadensis, Coptis, Xanthorhiza, which are tonics.

* These are not exactly the characters given by De Candolle, who includes all monopetalous orders with an inferior ovary in Calyciflora, and limits Corolliflora to the hypogynous monopetalous orders. But it seems to me more easy in practice to regard Corolliflora as equivalent to the Monopetala of Jussieu, while Thalamiflora and Calyciflora correspond to the Polypetala of that author, and Monochlamydea to his Apetalæ; and in a series so very artificial as this, we may be permitted, I think, to consult convenience.

This order divides into two principal sections.

I. Flowers regular. TYPICAL GENERA.-Ranunculus, Clematis, Adonis.

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Ceratocephalus orthoceras. 1. Flower. 2. Ripe fruit. 3. Ovaries of Ranunculus Krapfia. 4. Section of carpel and seed of the same.

Delphinium tricorne. 1. Petals and stamens. 2. Carpels. 3. A branch of ripe fruit.

2.-Anonacea. Trees or shrubs generally tropical. Leaves without stipules. Flowers axillary, large, and dull-coloured.

Sepals 3-4. Petals 6, coriaceous, with a valvular æstivation. Stamens indefinite; anthers adnate; filaments angular. Ovaries numerous. Fruit succulent or dry, with the carpels 1 or many-seeded, separate or consolidated. Embryo minute. Albumen ruminate.

The fruits

USES.-Aromatic and fragrant in most cases. of some are succulent and eatable, as the Custard Apple, Anona squamosa, and the Cherimoyer, Anona Cherimolia; those of others are hard, dry, and often jointed, as Habzelia aromatica, the Piper Æthiopicum of the shops, and are used as peppers. Some species are employed as febrifuges. TYPICAL GENERA.-Anona, Uvaria.

Anona furfuracea. 1. An expanded flower. 2. A vertical section of the androceum and gynæeceum, which latter forms a central and terminal tuft. 3. A vertical section of a carpel. 4. A vertical section of a ripe seed, showing the embryo and ruminated albumen.

3.-Menispermacea. Shrubs with a sarmentaceous habit. Leaves alternate. Flowers small. Flowers unisexual, usually very small. Sepals in one or several rows. Stamens monadelphous or distinct. Anthers turned outwards. Ovaries numerous, each with one style, sometimes soldered together into a many-celled body, which is occasionally, in consequence of abortion, 1-celled. Drupes berried, 1-seeded embryo curved, lying in albumen; radicle superior,

a

USES.-Roots of many bitter and tonic, as Cocculus palmatus, which yields the Calumba root; of others also diuretic, as Cissampelos Pareira, and Cocculus Bakis, the latter remedy used by the negroes of Senegal against intermittents. In the seeds a poison is formed, which in Anamirta Cocculus, the Cocculus Indicus of the shops, becomes extremely dangerous.

TYPICAL GENERA.-Menispermum, Cocculus.

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Cissampelos Pareira. 1. A male flower. 2. A female flower. 3. The vertical section of an ovary, which gradually curves the apex downwards, till, when it becomes the drupe 4, it acquires a horseshoe form. 5. A vertical section of a drupe, showing the embryo and albumen; a. is the true apex of the fruit, brought to the base as just described.

4.-Berberacea. Shrubs or herbaceous perennial plants. Leaves alternate, compound, usually without stipules. Sepals 3-4-6, in a double row. Petals sometimes with an appendage at the base. Stamens equal in number to the petals, and opposite to them; anthers opening elastically with a valve from the bottom to the top. Ovary solitary, 1celled. Seeds attached to the bottom of the cell, 1, 2, or 3; albumen between fleshy and corneous.

USES.-Bark astringent, and in Berberis yielding a yellow die. Fruit of Berberis acid; tubers of Bongardia eatable. TYPICAL GENERA.-Berberis, Epimedium.

5.-Nymphæacea. Herbs with peltate or cordate fleshy leaves, growing in quiet water. Sepals and petals imbricated,