would be superfluous to insist upon in this place. But in Cruciferee the 
stigmata are opposite to the placentc, terminating a sort of frame or replum, 
the two sides of which are often connected by a membranous septum, on 
the outside of which latter the ovula are arranged in a single row on each 
side; so that in many of the more highly developed plants of the order there 
are four placentee opposed to each other by pairs, and forming the inner 
edge of each side of the replum, which itself terminates in the stigmas. To 
this replum is attached on each side a deciduous plate, or valve as it is 
called, which has no vascular connexion with either the replum, stigmata, or 
pedicel. In consequence of this singular arrangement of parts, it has been 
found extremely difficult to understand the exact nature of the Cruciferous 
pistillum, or to reduce it to the rules which are known to govern the forma- 
tion of other compound pistilla. E 
According to Mr. Brown, and after him to M. Decandolle, the pistillum 
of Cruciferee is to be understood to consist of two confluent ovaria, united 
by their placente, two lamelle from each of which project into the cavity 
of the ovarium, and, meeting in the centre, coalesce and form the septum. 
This, however, does not remove the difficulty of the stigmata being opposite 
the placente, instead of alternate with them. I am not aware that any 
explanation of this point has been published by Mr. Brown; but M. De- 
candolle (Théorie Elémentaire, ed. 1. p. 183) accounts for it thus. He 
assumes that there are several kinds of simple pistilla, some of which are not 
to be found in an isolated state, but the possible existence of which he 
conceives to be demonstrated by eertain compound pistilla, that cannot be 
reduced to their simplest state without the admission of such a position. 
Among these supposititious simple pistilla is one called the Silequeile, 
“« which is formed originally of three pieces, the two lateral producing 
ovyula on their inner surface, and the outer (intermediate) one bearing no 
ovula ; pistilla of this description make up the fruit of Nympheacew, 
Papaveracew, and Cruciferw. When two pistilla of this kind are united 
by the external edge of their lateral pieces, they form those fruits which are 
said to have intervalvular placente ; each of these double placente is elon- 
gated into a style or stigma, simple in appearance, but in reality formed by 
two half styles grown together.” 
To maintain this theory, it is necessary to assume, in the first place, the 
existence of a simple pistillum, of a structure not only entirely hypothetical, 
but opposed to all we know of vegetable organization ; and, in the next 
place, that the stigmata of the order, although so simple in appearance that 
no trace whatever of composition can be found in them, are nevertheless 
each composed of two half stigmata in a state of cohesion. 
To us this explanation has always been unsatisfactory. It was dif- 
ficult to believe that rules of structure, well ascertained to be uniform 
in other plants, should be deviated from in Cruciferae ; especially when 
the irregularity observable in the arrangement of other parts of the flower 
was taken into account, It always appeared more probable, that the 
anomalous nature of the pistillum depended upon some irregularity cor- 
responding to that of the stamens, than upon peculiar laws appertaming 
to Cruciferee alone. 
This seems to be at length proved by Eschscholtzia, the fruit of which is 
so similar to that of Crucifere, that the uniformity of the laws under 
which they are both formed is not likely to be disputed. In this plant the 
pistillum is unilocular, with four stigmata, of which the two opposite ones 
