Elements of Physiophilosophy

by Lorenz Oken

1307. These seminal substances are deposited upon the alkaline, in opposition to the acid, side of the ovary; just as the root also represents the alkaline factor in reference to the stalk, in which appears the formation of acids.

1308. The seeds are the pinnate leaflets of the ovarian leaves, which continue in the condition of buds. They stand therefore as unclosed vesicles upon both edges of the carpel, as is particularly distinct in the legumens.

1309. As both edges are similar to each other, so there can be no ovary that has fewer than two seeds. In all one-seeded ovaries therefore one seed has been arrested, a fact that admits too of being demonstrated in the majority of cases.

1310. Every seed is placed at the extremity of a lateral rib of the carpel. These lateral ribs are called seed-bearers or placentæ. If such lateral ribs terminate before reaching the edge of the carpel, then the seeds stand upon the juncture or wall of the carpel. This does not, however, occur frequently, but only in the Siliquosæ, poppies, and some others. The elongated lateral rib, whereupon the seed hangs, is called umbilical cord. It is no peculiar organ, but only the seed-petiole.

1311. The direction of the seeds is possible in five ways, either upright and horizontal, transverse, or rising obliquely upwards and downwards in relation to the axis of the ovary.

1312. Every perfect seed (of Dicotyledons) is none other than a pentifoliar, involuted, pinnate leaf. The shell of the seed is the leaf-spathe or phyllodium, the two seed-lobes are the two posterior pinnate leaflets, while the germinal leaflets, or plumula, are the two anterior pinnate leaflets, together with the odd leaflet. The seed-rib or vascular cord (raphe) is continued into the seed-rootlet or radicle, and this into the petiole of the cotyledons.

1313. Every seed-coat must consist of three integuments; for every leaf consists of the lower and upper membrane, and of the interjacent parenchyma, in which the vessels are dispersed. The external leaf-membrane forms the most hard and coloured covering of the seed (testa), the internal the brown seed-tunic or pellicula; between the two lies the brown fibrous tissue, or desiccated parenchyma with the vessels.

1314. The hilum is the basis of the bud or of the seed-leaf; the seed-hole or micropyle is on the apex of the involuted bud, or rather of the phyllodium, in which the germ lies rolled up.

1315. Umbilicus and micropyle are united with each other by means of seed or leaf-rib (raphe). Both rarely stand opposite to each other, so as that the one should be below, the other above; but the apex of the leaf is usually so involuted that it again reaches the bottom of the leaf, whereby umbilicus and micropyle come into close and mutual approximation, as in the beans. The seed-petiole elongates itself into the seed-rib; this is continued upon the back of the phyllodium or testa, bends round, and returns again to the umbilicus, so as to describe a complete circle. The shell of the seed has consequently the form of the young fern or fern-capsule.

1316. The radicle is the continuation of the seed-rib, which is, however, dismembered itself, moves off, and thereby causes the micropyle to be, or, properly speaking, only renders it, free. The testa or seed-shell is consequently a phyllodium thrown over the germ, but the micropyle is the upper opening of the bud.