270 OBSERVATIONS ON PLANTS 



218] formed of two lamellae^ derived from the parietes of the 

 fruit. These lamellse are in many cases easily separable, 



before the Liuneaii Society in February, 1816, and printed in the twelfth volume 

 of their 'Transactions,' published in 1818. In this volume (p. 89), I observe 

 that " I consider the pistillum of all phfenogamous plants to be formed on the 

 same plan, of which a polyspermous legumen, or foUiculus, whose seeds are 

 disposed in a double series, may be taken as the type. A circular series of 

 these pistilla disposed round an imaginary axis, and whose number corresponds 

 with that of the calyx or corolla, enters into my notion of a flower complete in 

 all its parts. But from this type, and number of pistilla, many deviations take 

 place, arising either from the abstraction of part of the complete series of 

 organs, from their confluence, or from both these causes united, with conse- 

 quent abortions and obliterations of parts in almost every degree. According 

 to this hypothesis, the ovarium of a syngenesious plant is composed of two 

 confluent ovaria, a structure in some degree indicated externally by the division 

 of the style, and internally by the two cords (previously described), which I 

 consider as occupying the place of two parietal placentae, each of these being 

 made up of two confluent chordulse, belonging to different parts of the com- 

 pound organ." 



In endeavouring to support this hypothesis by referring to certain natural 

 families, in w^hich degradations, as I have termed them, are found, from the 

 assumed perfect pistillum to a structure equally simple with that of Compositse, 

 and after noticing those c-ccurring in Goodenovire, I add, *' The natural order 

 Cruciferse exhibits also obliterations more obviously analogous to those assumed 

 as taking place in syngenesious plants ; namely, from a bilocular ovarium with 

 two polyspermous parietal placenfse, wliich is the usual structure of the order, 

 to that of Isatis, where a single ovulum is pendulous from the apex of the 

 unilocular ovarium ; and, lastly, in the genus 13occonia, in the original species 

 of wliich {B. fj'utesccns)^ the insertion, of the single erect ovulum has the same 

 relation to its parietal placcntfe, as that of Compositee has to its filiform cords, 

 a second species {B. cordafa) exists, in which these placentaj are poly- 

 spermous." 



From this quotation it is, I think, evident, that in 1818 I had published, in 

 my essay on Compositte, the same opinion, relative to the structure of the 

 pistillum of Cruciferse, which has since been proposed, but without reference 

 to that essay, by M. De Candolle, in the second volume of his ' Systenia 

 Naturale ;' and I am not aware that when the essay referred to appeared, a 

 similar opinion had been advanced by M. De Candolle himself, or by any other 

 author ; either directly stated of this family in particular, or deducible from 

 any general theory of the type or formation of the pistillum. I am persuaded, 

 however, that neither M. De Candolle, when he published his ' Systema,'nor M. 

 Mirbel, who has very recently adverted to this subject, could have been ac- 

 quainted with the passage above quoted. This, indeed, admits of a kind of 

 proof; for if they had been aware of the concluding part of the quotation, the 

 former author would probably not have supposed that all the species referred 

 to Bocconia were monospermous {S,i/st. Nat. 2, p. 89) ; nor the latter that 

 they were all polyspermous. {Mirbel in Ami. des Scien. Nat. 6, p. 2G7). lle- 

 specting Bocconia cordata., though it is so closely allied to Bocconia as to afford 

 an excellent argument in favour of the hypothesis in question, it is still 

 suSieiently different, especially in its polyspermous ovarium, to constitute a 

 distinct genus, to which I have given the name (Macleaya corda(a) of my 

 much valued friend Alexander Macleay, Esq., Secretary to the Colony of New 

 South Wales, whose merits as a general naturalist, a profound entomologist, 

 and a practical botanist, are well known. 



