252 



On some remarlcahle Plants in the 



seemed to me to present no traces of composition, or any 

 such difference in texture between the superficies and centre, 

 as might have been expected to be presented in some part 

 at least; and also by the fact that the lines of communication 

 with the locelli of the ovarium, and which, in my opinion, 

 alone allow of the passage of boyaux, open on the surface of 

 the base of the column. 



The third mode of explanation, suggested by the irregu- 

 larity in position of certain placentas, and by the views of 

 Mr. Brown*, regarding the origin of the stigma from the 



* In a paper on the capsule of Papaveracese, and stigma of Cruciferae 

 by Mr. J. W. Howell, O the situation of the stigmatic rays of Papa- 

 veraceae is explained by the assumption of their being compound, an 

 opinion also held by Mr. Brown. There is also another partial coinci- 

 dence of opinion regarding the improbability of the axis of a carpel leaf 

 bearing ovula. 



Mr. Howell, however, arrives at the conclusion that this composition 

 of the individual stigmata of a syncarpous pistillum is only occasional, 

 admitting the existence of simple stigmata in single carpels. Whereas 

 Mr. Brown setting out from the consideration of the simplest form of 

 the vegetable pistillum, advocates the opinion of their being always 

 compound, explaining their apparent opposition by confluence. 



From the note by the Editors appended to Mr. Howell's valuable pa- 

 per, it might be made out that Mr. Howell's observations on the stig- 

 mata were of a more general nature than they are ; whereas they are 

 limited to Papaveracese, and further regard the difference between a 

 Papaveraceous and Nymphaeaceous stigma as an arbitrary one, " serving 

 to separate by abruptly defined limits those otherwise nearly related 

 orders. "(2) 



Both Mr. Brown's and Mr. Howell's observations appeared publicly 

 in 1840 ; but there can be no doubt that so far as Papaveraceae are con- 

 cerned, Mr. Howell is anticipated by M. Kunth, whose observations 

 appeared in 1838, *' in a printed hook.'' 



On this subject of the stigma, I have lately ventured to offer some 

 remarks, derived from conclusions suggested to me independently of 

 either Mr. Brown's remarks or the paper by Mr. Howell. The sub- 



(1) Ann. Mag. Nat. Hist. v. 10. 65. p. S48. 

 (2) op. cet. p. 249. 



