Plate 11.

Cooper fealp

Lob'd leaf Passion Flower 17 Pinnate leaf, Rese 14 Frend, Fern Bearing Seed on the Back 15 Stipe Fern 16 Simple leaf Convolvulus 16+ 20 Thorns Hippophae rhamnoides. Prickle Rose.. 24 Hair, Nettle 25 Whort, Dead Neule... 26 Cluster, Bunch Currants... 27 Spike, Orchis 28 Corymb, Spiraea Opulifolia 29 Farcicle, Sweet William 30 Head or Tuft, Thrift.31. Umbel, Hemlock 32 Gyme, Laurustinus.

London Published Feb 11808 by Longman Hurst, Rees, & Orme Paternoster Row.

fruit of the pea kind, solitary, formed of two oblong valves, without any longitudinal partition, and having the seeds ranged along one of its margins only. 4. Drupa, fig. 43, a stone-fruit, like the peach and cherry, has a fleshy undivided coat, containing a single hard stone or nut. 5. Pomum, fig. 44, an apple, contains a capsule of several cells in a fleshy coat. 6. Bacca, fig. 45, a berry, is fleshy, without valves, containing one or more seeds lodged in pulp, as the gooseberry and currant. Some berries are compound, as the raspberry; others are of a spurious kind, the pulp originating from some part not properly belonging to the fruit, as the calyx in the mulberry, and the receptacle in the strawberry. And, fig. 46, Strobilus, a cone, originates from a catkin, become hardened, and enlarged into a compound seed-vessel, as in the fir, birch, &c.

6. Semina, the seeds, fig. 47, the most essential of all the organs of fructification, being those to which all the others are subservient. The seeds are composed of several parts, the most important of which is the embryo, or germ. Linnæus calls it corculum, a little heart, in allusion to its shape in the walnut, in which, as well as in the bean, and other leguminous plants, it is readily observed. Its position is either upright, horizontal, or reversed. It is generally lodged within the substance of the seed, except in grasses. Cotyledones, the cotyledons, or seed-lobes, are intimately connected with the embryo: they are almost universally two in number, though in the fir tribe they are more numerous. When the seed has sent its root into the ground, these organs generally rise above the surface, and perform the functions of leaves till the proper foliage is produced. Plants, therefore, for the most part are properly denominated dicotyledones. Such as are called monocotyledones have really no proper cotyledon, and the first part that appears above the ground from their seed is a real leaf. Albumen, the white, makes up the chief bulk of some seeds; but never rises out of the ground, nor assumes the office of leaves, being destined solely to nourish the embryo till its roots can perform their office. It may be observed in grasses, corn, and palm-trees: in some it is farinaceous; in others as hard as a stone, witness the date. The nutritious matter, which in these plants constitutes the albumen, is in others lodged in the substance of the cotyledons. Vitellus, the yolk, was first named by Gærtner, and is supposed by him to furnish nourishment to the embryo. Dr. VOL. I.

Smith, however, has first suggested that the vitellus is rather a subterraneous cotyledon, see his "Introduction to Botany," 292. Testa, the skin, a single or double membrane envelops the parts hitherto described, bursting irregularly when its contents swell in germination. Hilum, the scar, is the point of attachment through which nourishment is conveyed to the seed while growing. This point is always considered as the base of the seed in description.

Seeds are often accompanied by appendages or accessory parts, as pellicula, the pellicle, which adheres to their outside in the form of a fine skin, sometimes downy, sometimes of a mucilaginous substance. An instance of the latter occurs in Salvia verbenaca, whose seeds are celebrated for extracting particles of dust from the eye, by enveloping them in its mucilage, which swells on the application of moisture. Arillus, the tunic, is a complete or partial covering of a seed, fixed to its base only, and more or less closely enfolding its other parts. In the euonymus it is pulpy and orange-coloured, the seed itself being crimson. The mace which enfolds the nutmeg is of this nature. Many of the orchis tribe are enveloped in a membranous tunic, extending beyond the outline of the seeds, and giving them a light chaffy appearance. The elegant wood-sorrel has an elastic arillus, like a little bag, serving to project the seeds to a distance. In the carex the same part is in some degree inflated and membranous. The covering of the seeds in the cynoglossum is considered by Dr. Smith as a testa rather than an arillus. Pappus, the seed-down, in its most strict sense, is the chaffy, feathery, or bristly crown of several seeds that have no seed-vessel, as in the dandelion, thistle, scabious, and others. In a more general sense pappus is applied to any feathery or downy appendage to seeds, even though lodged in a pericarpium. Cauda, a tail, is an elongated appendage, originating from the permanent style. It is generally feathery, as in the virgin's bower, clematis. Rostrum, a beak, has a similar origin, but usually belongs to a seed-vessel. Ala, a wing, is a dilated membranous appendage, serving to waft seeds along in the air. To all the above may be added various spines, hooks, scales, and crests, generally serving to attach such seeds as are furnished with them to the rough coats of animals, and so to promote their dispersion. This appears to be the final purpose of the awns of grasses in general. Q q

7. Receptaculum, fig. 48, the receptacle, is the common base or point of connection of the parts of fructification. It is essential, inasmuch as it must exist in some form or other. This part, however, comes chiefly into no. tice when it assumes any peculiar form, as in compound flowers; the dandelion, daisy, and thistle, for instance. In some of this class it is naked, scaly, hairy, or cellular, and such circumstances afford excellent generic characters. Such of the natural order of Proteacea as have aggregate flowers are also furnished with as conspicuous a receptacle as the compound flowers. The receptacle of the seeds is a term used for the part to which they are attached in a seedvessel.

OF THE CLASSIFICATION OF PLANTS.

The species of plants, as well as of all other natural productions, are so immensely numerous, that the most superficial observer must be aware of the necessity of some regular mode of arranging them, as well as of naming and distinguishing them, in order to acquire or to retain any clear knowledge of their natures, differences, or comparative uses. Hence the distribution of plants into trees, shrubs, and herbs, into eatable, medicinal, or hurtful kinds, was very early conceived; for the human mind is naturally prone to method and combination. When the subject came to be scientifically studied, various plans were formed, as different in ingenuity and utility as possible, proceeding on various principles, but all aiming at the same end, the commodious arrangement of plants. The authors of these various schemes seem all, as far as they considered the matter with any such view, to have thought their own plan most consonant with that natural classification which every one at first sight perceived to exist in the creation; but a little experience proved that the clue of nature soon eluded their grasp.

Linnæus, the first person who took a very comprehensive and philosophical view of the laws of system, and at the same time carried them most happily into effect, for the purposes of utility and facility, was the first to perceive the difference between a natural arrangement and an artificial one. He ever considered the former as the great desideratum of philosophical botany, and indeed as necessary to be kept in view by all who describe or define new discovered plants; while the latter was to be adopted for ready use and convenience, just as

words are arranged in a dictionary according to their spelling, without any regard to their derivations or analogical meanings. The same great naturalist was also, from the first, aware of the essential importance of the principle laid down by Gesner and Cæsalpinus, as we have already stated, that plants ought to be arranged by their parts of fructification alone, and not by their general habit or structure independent thereof. Hence he denominates heterodox all such systematics as class vegetables by their leaves, roots, uses, times of flowering, or places of growth, for, strange to tell! there have been such; and he esteems truly orthodox those botanists only who derive the characters of their systems from the flower and fruit, in which, as he expresses it, the true form or essence of their being is displayed. On this point all botanists are now agreed, but they differ widely concerning the eligibility of a natural or an artificial system for daily use, as well as the principles upon which each ought to be founded.

The earlier systematics began with the consideration of the seed and seed-vessel, forming their classes upon the situation of the embryo, whether at the top or base of the seed, and the number of the seeds and seed-vessels, or their cells, in different plants. Some, as the great English naturalist Ray, took into consideration, over and above the fruit and its parts, the form and number of the parts of the corolla, and even the leaves and roots, which altogether make but a motley jumble of principles; but in a second attempt this learned man was more uniform and successful in his scheme. Others founded their systems on the corolla alone, as Rivinus and Tournefort, whose methods are elegant and attractive at first sight, but far more unphilosophical, far more difficult in practice, than those founded on the fruit. The authors of these various systems disputed with great warmth concerning their respective merits, and each had his followers and advocates. Many other methods were contrived, partaking, more or less, of the principles of the few great leading systematics who contended for the botanical sceptre, and frequently borrowing from them without due acknowledgment. All these systems have now passed away, at least with respect to practical use. They are the study of the botanical antiquary, and they are instructive to the student of philosophical arrangement in general; but no work that treats of plants is arranged