The Vegetable World: Being a History of Plants, with Their Botanical Descriptions and Peculiar Properties

Three parts are observable in the pistil—the ovary,

the style, and the stigma. These three parts are very apparent in Fig. 213, representing the pistil of the Chinese Primrose, where the letters stig. indicate the stigma, the letters sty., the style, by the letter 0, the ovary. The ovary is the part of the vegetable destined to contain the seed, that is, the ovules, which, when fertilised and developed, become the seeds. The part which supports the ovules, which is generally rather thick, is called the placenta; it is indicated ¥is,2!3;Pistiot in Fig. 213 by the letter Pp, above the receptacle 7.

The top of the ovary is prolonged by a filament, either long or

short, which is called the style, and is analogous to the mid-rib in leaves. The style carries a glandular appurtenance on its summit, destined to receive the pollen-grains, and to help fecundation; this is the stigma.: The style is not a solid cylinder, as we might think at first sight; on the contrary, its axis forms a sort of canal leading into the ovary, and descending to the vicinity of the ovules. The stigma, which is the upper part of the pistil, is very variable in form; it is essentially formed by a mass of thin, transparent cells, loosely united and coated over with a gummy, mucilaginous matter. It is thus perfectly well fitted to receive and retain the pollen-grains. -

The carpels have a greater tendency than the more external - organs to unite with each other: this is, n0 doubt, either owing to their proximity, or to the pressure of the external organs, assisted by their position in regard to each other. » } This junction takes place either by the a _ ovaries alone, or by the ovaries, styles, and w stigmas, or by the stigmas alone. en two or more carpels are united by means of the ovaries, an ovary results composed of several partial ones, there being 8

Fig. 214.—Pistil of Fetid Many cells as there were carpels at first. In capes the Bastard Hellebore (Fig. 214) the june-tion of the ovaries takes place at the base only; m the Corn-cockle (Fig. 215), about half way up. But most frequently the junction takes place at the summit. When the styles are joined together, at least in some observable portions of their length, there results from this cohesion a style single in ap-by as many pearance, but in reality constituted partial styles as there were carpels. In this case the number of free stigmas will, if they are simple, indicate the number of cells in the ovary: The partial stigmas may also unite, and constitute pais -Ovnes of 2 8 stigma, in appearance single, but often - us """ divided as to indicate by the number of its divisions the number of carpels constituting the pistil. The

absolute number of cells in a pluri-locular ovary is. subject to variation, but is generally three, then comes the number two and five, but very rarely four. This number, besides, is not always the same in the different ages of the flower; it sometimes happens that they are multiplied by the formation of partitions, afterwards further developed, as in the Vervains and the Ladiatee, which, at first, have only two cells, but later show four, by the partition of each of the primitive cells into two compartments. This is also seen in the Flax-plants, the five primitive cells of which divide at a given time into two, by a partition of new formation. + These supplementary partitions which thus mask the first structure of the ovary, are called spurious dissepiments.

The ovary is usually apparent or free, and perceptible by looking into the bottom of the flower; it is then called a superior ovary, as in the Poppy (Fig. 216) and Lily. At other times only the summit of the ovary shows itself at the bottom of the flower, and it is united with the receptacle, and must be looked for underneath the flower; the ovary is then called inferior or adherent, as in the Coffee-plant, Madder (Fig. 217), and Melon-plants. We have stated above that the small bodies attached to the placenta are called ovules, and 8 18;,Draryofthe that afterwards they become seeds. These ovules are composed of a small central body or nucleus, adhering by its base to a double sac, showing only a very small aperture corresponding to the free summit of the nucleus. The external sac is called primine, and the internal sac secundine. The aperture of this double envelope is the microphyle. The point of adhesion of the nucleus with “its integuments is called the chalaza. Some ovules have no primine, and some have neither primine nor secundine. But these cases are rare. The point at which the ovules are attached to the placenta, either directly or in-: directly by means of a small thread or Juniculus, bears jig 275, Mader Boot the name of hilum.

Ovules are not all of the same form. The ovule of Rhubarb

(Fig. 218) is shaped like an egg. Its hilum is diametrically ' opposite to the microphyle. This kind of ovule is called orthotropal.

In the Hellebore, on the contrary, the ovule has its point of attachment placed near the microphyle, and we notice a cord-like swelling on one of its sides, which reaches all along it, and is called raphe (Fig. 219). This kind of ovule is called anatropal.

In the French Bean the ovule has in the same way its point of

Fig. 218.—Ovule of Rhubarb. Fig. 220.—Ovule of the Haricot. Fig. 219.—Ovule of Hellebore.

attachment placed near the microphyle, but as it has no raphe and is bent, it is said to be campylotropal (Fig. 220).

Such are three principal forms of the ovule. The second is the most common, and the first is the most rare.

Tue REcEPrACLE.

The calyx, corolla, stamens, and pistils, are inserted in the extremity of the floral peduncle, which is called the receptacle. Its form is very variable. In the Ranunculus it is conical; the calyx, corolla, stamens, and pistil are inserted and ranked in succession on its sides, the last organs nearly at its summit. In _ the Myosurus (Fig. 221), it is so much " lengthened, that it resembles a 8 spike, of which the flowers would the carpels. As in these circumstances the stamens are inserted underneath the pistils, these stamens are said to be In the Peach (Fig. 222) ‘ Fig, 221.—Receptacle of Myosurus. gnd the Apricot, the receptacle has the form of a cup, at the bottom of which is the pistil, whilst the calyx

and the stamens are inserted in the side. These last surround the pistil, and are called perigynous.:

Fig. 222.— Receptacle of the Peach-blossom.. Fig. 223.—Receptacle of the Burnet Rose.

In the Rose (Fig. 223) the receptacle is hollowed out, so as to take the form of a bottle, the bottom of which is occupied by the carpels, and on the upper edges are inserted the sepals, the petals, and the stamens. These are also perigynous. In all the examples we have hitherto cited, the pistil does not form any adherence with the receptacle. Also, in every . case, even in

receptacle is

Fig. 224.—Adherent Ovary of Saxifrage. rior. But it is not always thus. The receptacle, hollowed out like a cup, is joined rather frequently with the ovarian part of the carpels, which it encloses; and this junction is

Fig, 225.—Adherent Ovary of made more or less high up, so as to show the Fuchsia. every possible degree of adherence. We see this in the flower of the Saxifrage (Fig. 224), the Apple-tree, Medlar, and Myrtles; also in the flowers of the Fuchsia (Fig. 225). The ovary is then called adherent.

THE FRUIT.

Flowers have but a short-lived existence;after fecundation they disappear; the ovary, rendered fruitful and enlarged in size, alone remains. The withered and dried-up fragments of the corolla strew the ground, or are carried about by the wind. But though the plant has lost much that embellished it, though it no longer possesses the brilliant ornaments which attracted observation and charmed all eyes, it still retains an interest of its own. A new decoration replaces the former one, leaving nothing to reg? ot 1D the change. To the white flowers of the wild rose succeeds the young fruit, tinted with a pleasing green. The mountain ash, the medlar, and the buckthorn, in casting off delicately-tinted corolla, display their fruit, which soon changes to a bright ™ colour. The perfumed flowers of the orange-tree are succeeded by

the golden apples of the Hesperides; the delicate corolla of the cherry-tree is followed by the purpled globes of its fruit. The verdure of our corn fields, ripened by the summer’s sun, now bend under the weight of the golden grain. We can now admire the soft down of the peach, the enormous globes of the melon-tribe, the firm and juicy pulp of the sweet-tasting plum, the nutritious substance of the legumes, the purple bloom of the grape, gilded by the autumnal sun! If flowers awake in us a feeling of happiness and joy, fruits bring with them the promise of abundance and wealth. When fecundation is effected, life is concentrated in the ovules and in the ovary, enclosing and protecting them. These organs continue to grow, and soon present new characteristics. The ovule becomes the seed, the ovary becomes the pericarp, and the two together constitute the fruit. The fruit is, then, the ovary which has ripened, or sef, as the gardeners say.

The appearance of the fruit differs according as the ovary is free or adherent. In the former case, the fruit only shows on its surface a scar on the style, and sometimes at its base the remains of the calyx, the corolla, and the androceum. In the second, the fruit presents at its surface, and near the summit, the scars left at the insertion of the sepals, petals, and stamens. Thus it is, that an apple, a quince, or a gooseberry, all resulting from the ripening of an adherent ovary, are provided with an eye, which is completely wanting in the plum, the cherry, and the peach, these latter fruits resulting from the ripening of a free ovary.