16 



than the two others. Upon opening this pistilhim we find that there are two 

 parietal placentae corresponding with the smaller stigmata, and that there 

 are no placentae opposite the larger stigmata ; in other words, that it is 

 formed of four simple pistilla, two of which are opposite and ovuliferous, 

 with their placentae in the usual place, alternating with themselves; and two 

 nearly abortive, destitute of placentae, consequently not ovuliferous, and so 

 nearly suppressed by the superior energy of their two neighbours, that their 

 existence would have been unknown but for the stigmata which indicate their 

 presence. This is one way of understanding Eschscholtzia ; but as the ovula 

 are not inserted in the placentae in a double row, but rather confusedly 

 arranged in several rows, it may also be assumed that the lateral, imperfect, 

 half-obliterated stigmata have a line of placentae, with ovula appertaining to 

 themselves, but so confounded with the placentae of their lateral and more 

 powerful neighbours, that, in consequence of their close approximation, they 

 cannot be distinguished. We, however, incline to the former of these two 

 opinions. Let this be as it may, upon either supposition, the structure of 

 Cruciferous pistilla is, we think, susceptible of explanation. We shall, for 

 convenience, reason upon the former of the two hypotheses. 



"If we compare the fruit of Eschscholtzia and Cruciferae, we shall at 

 first, perhaps, be led to believe that while they have a certain degree of 

 resemblance in some points, they nevertheless differ widely in others of more 

 importance : we find both of them with two opposite parietal placentae, con- 

 nected with a quaternary arrangement of the other parts of the flower, and 

 that in both instances their placentae are opposite to stigmata. But we also 

 see that in Cruciferae dehiscence takes place by the separation of two valves 

 from the sides of the siliqua, leaving the placentae undivided ; while in 

 Eschscholtzia it takes place through each placenta, half of which, therefore, 

 adheres to each edge of the two valves into which the fruit finally separates. 

 But if we look into their structure a little more narrowly, we shall perhaps 

 find that these differences are not only capable of reconciliation, but that 

 they explain each other. 



" The fruit of Cruciferae is separable into four parts ; that is to say, into 

 two valves without stigmata, and two double placentae without valves: in 

 Eschscholtzia there are two valves with placentae and stigmata, and two 

 stigmata without valves or placentae. But suppose that the two valves of 

 Cruciferae had stigmata, as they should have (and a tendency to produce 

 which actually exists in Iberis umbellata), and that the two stigmata of 

 Eschscholtzia had valves, as would be regular, what would then be the dif- 

 ference between the two? It would be reduced to nearly this: that in 

 Eschscholtzia the two placentiferous pieces would occupy the greater part 

 of the pcricarpium, the two sterile valves being very small; while in Cru- 

 ciferae the two placentiferous pieces Avould be very small, the chief part 

 of the pericarpium being occupied by the sterile valves." 



Such was the idea I was led, by tlie curious structure of Eschscholtzia, to 

 entertain in 1828, upon the fruit of Cruciferae. 1 am aware that it is possible 

 to explain the peculiar economy of the replum of Cruciferae by that of Carmi- 

 chaelia, alltd that the line of dehiscence in fruit is no evidence of the plan 

 upon which it has been constructed. I also know that a less paradoxical 

 way of understanding the structure of the Siliqua, is to take two confluent 

 carpella, each of which has a 2-lobed or 2-horned stigma, for the type of 

 such a fruit; upon which supposition each apparent stigma of the siliqua 

 will be made up of two halves : and moreover I have been shewn by Mr. 

 Brown some instances of monstrous formation, which seem to confirm such 

 an opinion. Nevertheless, I wish to record, in this book, my view of the 

 subject, whether it shall be ultimately found to be accurate or inaccurate, for 



