Explanation of the Plates. Explanation of Plates I and II. Fig. 1. The seed vessel of the horse the plates. chestnut, cut open horizontally. a, a, a, a, the impregnating vessel, or vessel of life, proceeding from the interior of the seed vessel. k, k, the string that stretches to attain the heart, and which, I think, is mistaken for the radicle. b, b, b, b, the nourishing vessels (marked by dotted lines only, to distinguish them), which always proceed from the exterior of the seed vessel. d, d, d, d, the pocket. Note. Similar letters of reference denote the same parts in all the figures. Fig. 2. Half a similar seed vessel cut longitudinally, showing the first appearance of the seed vessel in the bud of a female flower. Fig. 3. The seed of the horse chestnut, Fig. 4, that of the peach, and Fig. 5, that of a grass, as they first appear in the bud of the flower. c, the corculum. e, the cuticle, or outer skin of the kernel. The seed of the peach is delineated in the seed vessel; the others are taken out of it. Figs. 6, 7, 8. The same seeds in their second stage of growth. Figs. 9, 10, 11. The three seeds in their third stage, when impregnated; the pocket joining the corculum, and the string k disappearing. Figs. 12, 13, 14. The seeds in their fifth stage: the corculum perfected, the seminal leaves almost complete, and the nourishing vessels on both sides of the seeds. Figs. 15, 16, 17. The three plants, showing only the embryo of the chestnut and peach. This is now as complete as it ever is, till placed in the ground in the seed. It is given thus, to show, that there is no radicle to it; and that the root, which will grow as soon as it is placed in the ground, can proceed only from x. This is easily seen, by comparing these with the plants where the root is annexed, which is merely filled out, and grown longer; and where the heart is still to be found, marked by a dotted circle. g, g, the cotyledons. i, i, the primordial leaves. Figs. 18, 19. The bean and its embryo from Dr. Smith. g, the cotyledons. h, the holders; which show how little they |