seem now to be generally agreed upon referring Nymphceacece to Dicotyledons. I observe moreover, that Von Marties, who once adhered to the opinion, that Nymphceacece are Monocotyledonous, and nearly related to Hydrocharacece, (see Hortus Regius Monacensis, p. 25) now places the order in its true position near Ranunculacece (see Conspectus, No. 188). Those who are curious to investigate the subject are referred to DeCandolle's Memoir, in the first volume of the Transactions of the Physical and Natural History, Society of Geneva. In this place it will be sufficient to advert briefly to the proof, that is supposed to exist of Nymphceacece, being Dicotyledons. In the first place, the structure of the stem is essentially that of Exogens, according to MirbePs examination of the anatomy of Nuphar luteum, in the Annales du Museum, vol. 16, p. 20; and of Nelumbiwn, the close affinity of which, with Nymphceacece, no one can possibly doubt, in the same work, vol. 13, t. 34. In both these plants the bundles of fibres are described as being placed in concentric circles, the youngest of which are outermost; but they all lie among a great quantity of cellular tissue: between each of these circles is interposed a number of air-cells, just as is found in Myriophyllum and Hippuris, both undoubted Dicotyledons in the opinion of every body, except Link, who refers the latter to Endogens, (see Gewachsk, 6, p. 288). Secondly, the leaves are those of Dicotyledons, and so is their convolute vernation, which is not known in Monocotyledons, and their insertion and distinct articulation with the stem. Thirdly, the flowers of Nymphceacece have so great an analogy generally with Dicotyledons, and particularly with those of Magnoliacece, and their fruit with Papaveracece, that it is difficult to doubt their belonging to the same group. Fourthly, the reasons which have been offered for considering the embryo Monocotyledonous, however plausible they may have appeared, while we were unacquainted with the true structure of the ovule of other plants, have no longer the importance that they were formerly supposed to possess. The sac, to which I have already alluded, to which so much unnecessary value has been at- tached, and which was mistaken for a cotydelon by Richard, is no doubt analogous to the sac of Saururus and Piper, and is nothing more than the remains of the innermost of the membranous coats of the ovule, usually indeed absorbed, but in this and similar cases remaining and covering over the embryo. Brown (appendix to King's voyage) considers it the remains of the membrane of the Amnion. DeCandolle assigns a further reason for considering Nym- phceacece Dicotyledons, that they are lactescent, a property not known in Monocotyledons. But in this he is mistaken ; Limnocharis, a genus belonging to Butomacece, is lactescent. It must moreover be observed, that the arrangement of the woody matter of Nupha-r luteum is far less obviously exogenous than weuld be supposed from the manner in which it is described by Mirbel." See Lindley's Natural System of Botany, 2d Ed. page 11.
This order in addition to the peculiarities above cited, affords one of the best examples of the gradual transition of sepals into petals, and petals into stamens, there being intermediate rows of both, that belong neither to the one set, nor the other. In some as Nymphcea, the disk is so remarkably developed, that it elevates itself as high as the top of the ovary, to the surface of which it adheres, and the stamens being carried up along with it, appear to proceed from the top of the ovary ; and " in the genus Barclaya, the petals also are carried up with the stamens, on the outside of which, they even co-here into a tube, so that in this genus we have the singular instance, of an inferior calyx, and superior corolla, in the same plant." Lindley.
As the affinities of this order have been so repeatedly and carefully examined by the ablest Botanists of the age; I shall in preference to attempting to state them in my own words; again have recourse to Dr. Lindley's assistance, and introduce another extract from his excellent work.
"Supposing this order to be exogenous, and Dicotyledonous, a fact about which, there appears to me to be no doubt, its immediate affinity will be with Papaveracece, with some genera of which it agrees in the very compound nature of the fruit, from the apex of which the sessile stigmas radiate, in the presence of narcotic principles and a milky secretion, and in the great breadth of the placentee. Nymphceacece are also akin to Magnoliacece, with which they agree in the imbricated nature of the petals, sepals, and stamens; to Nelumbiacece their close resemblance is evident; with Ranunculaceae, they are connected through the tribe of Paeonies, with which they agree in the dilated state of the disk, which, in Paeonia papaveracea and Moutan, frequently rises as high as the top of the ovaries, and in the indefinite number of their hypogynous stamens; but in Ranunculaceae, the placentas only occupy the
