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This pistil consists of a number of carpels, arranged in many rows very regularly on a central receptacle; each carpel has a style, ending in a slightly-lobed stigma; and an ovary, wherein lies one single ovule, or young seed. The course of the transformation of this apparatus into fruit is highly curious and interesting.
I also met with a tree about twenty feet high belonging to the natural order Dilleniaceae, with large spreading branches, producing at the axilla of the leaves from three to five large yellow flowers, with a row of red appendages surrounding the carpels, and a fine species of Calophyllum, with large dark green leaves, six to eight inches long, two and a half to three inches broad, beautifully veined, and with axillary racemes of white, sweet-scented flowers; the seed being a large round nut with a thin rind, of a yellowish-green colour when ripe.
The general characteristics of these are the calyx flattish at the bottom, and five-cleft; five petals; many stamens inserted into the calyx with the petals; many fleshy carpels arranged on a somewhat elevated receptacle, with lateral style, near the points of the carpels.
Lindley says: 'In the one case, the receptacle robs the carpels of all their juice, in order to become gorged and bloated at their expense; in the other case, the carpels act in the same selfish manner on the receptacle.
The outer rind is so tough and strong, that no matter from what height the fruit fall it is never crushed or broken. From the base of the fruit to its apex, five faint lines may be traced running among the spines. These form the divisions of the carpels where the fruit can be cut open with a sharp knife, though requiring a considerable exertion of strength.
In Gymnosperms we have seeds, and the carpels may become modified and close around these, as in Pinus, during the process of ripening to form an imitation of a box-like fruit which subsequently opening allows the seeds to escape; but there is never in them the closed ovary investing from the outset the ovules, and ultimately forming the ground-work of the fruit. Germination of Seed.
Clambering over some neglected fence, often to nearly 20 feet in height, this vigorous-growing plant is seen to best advantage, the three or five-lobed leaves and festoons of greenish-white, fragrant flowers, succeeded by the curious and attractive feathery carpels, render the plant one of the most distinct and desirable of our native wildlings flowering in August. C. VITICELLA. Spain, 1569.
Numbers are of course less liable to changes, but the numbers of the rays of umbels, or ray-florets in the composites, of pairs of blades in pinnate leaves, and even of stamens and carpels are known to be often exceedingly variable. The smaller numbers however, are more constant, and deviations from the quinate structure of flowers are rare.
If you observe the berries of the common brambles, the dewberry, and the cloudberry, you will find them to be all thus formed, though the number of grains, as these swollen carpels are called, differ materially the dewberry often maturing only one or two, while the raspberry, and some kinds of the brambleberry, present us with twenty and more. The raspberry was but little noticed by the ancients.
The ovary is situated in the middle of the flower, and in some instances two have been observed. This is also to be considered as a case of atavism. All these parts of the adventitious flower are more or less subject to arrest of development, in a later stage. They may even sometimes become abnormal. Stamens may unite into pairs, or carpels bear four stigmas.
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