11 



except Link, who refers the latter to Endogense (see Gewuchsk. 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 dis- 

 tinct articulation with the stem. Thirdly, the flowers of Nyraphseaceae have 

 so great an analogy generally with Dicotyledons, and particularly with that 

 of Magnoliacese, and their fruit with Papaveraceae, that it is difficult to doubt 

 their belonging to the same class. 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 ovulum of 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 attached, and which was 

 mistaken for a cotyledon by Richard, is no doubt analogous to the sac 

 of Saururus and Piper, and is nothing more than the remains of the inner- 

 most of the membranous coats of the ovulum, usually indeed absorbed, but 

 in this and similar cases remaining and covering over the embryo. Mr. 

 Brown {Appejidix to King's Voyage) considers it the remains of the mem- 

 brane of the amnios. M. Decandolle assigns a further reason for considering 

 Nymphseaceae Dicotyledons, that they are lactescent, a property not known 

 in Monocotyledons. But in this he is mistaken ; Limnocharis, a genus 

 belonging to Butomea?, is lactescent. Independently of the peculiarities 

 to which I have now alluded, this order is remarkable in some other respects. 

 It offers one of the best examples which can be adduced of the gradual 

 passage of petals into stamens, and of sepals into petals : if attentively ex- 

 amined, the transition will be found so gradual that many intermediate 

 bodies will be seen to be neither precisely petals nor stamens, but both in 

 part. The development of the disk, which is so remarkable in Nelumbonese, 

 takes place here in various degrees. In some, as in Nuphar, it is merely an 

 hypogynous expansion, out of which grow the stamens and petals; in others, 

 as Nymphoea, it elevates itself as high as the top of the ovarium, to the 

 surface of which it is adnate, and as the stamens are carried up along with 

 it, we have these organs apparently proceeding from the surface of the 

 ovarium : in another genus, the Barclaya of Dr. Wallich, the petals are also 

 carried up with the stamens, on the outside of which they even cohere into a 

 tube, so that in this genus we have a singular instance of an inferior calyx 

 and a superior corolla in the same plant. 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 Papaveraceae, 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 

 placentse. They are also closely akin to Magnoliaceae, with which they 

 agree in the imbricated nature of the petals, sepals, and stamens ; to 

 Nelumboneas their close resemblance is evident ; with Ranunculaceee they are 

 connected through the tribe of Paeonies, with which they agree in the dilated 

 state of the discus, which, in Pseonia papaveracea and Moutan, frequently 

 rises as high as the top of the ovaria, and in the indefinite number of their 

 hypogynous stamens; but in Ranunculaceee the placentae only occupy the 

 edge of each of the carpella of which the fruit is made up ; so that in Nigella, in 

 which the carpella cohere in the centre, the seeds are attached to the axis, while 

 in Nymphseaceae the placentae occupy the whole surface of each side of the in- 

 dividual carpella of which the fruit is composed. But if such are the undoubted 

 immediate affinities of Nymphaeaceae, it is certain that some strong analogies 

 exist between them and Hydrocharideee, to the vicinity of which they are 



