18431862] CRUCIFEROUS FLOWERS 289 



observe, I do not know that I shall have time, for I have just Letter 616 



become wonderfully interested in experimenting on Drosera 



with poisons, etc. If you send any Fumariaceous plant, send 



if you can, also two or three single balsams. After writing 



to you, I looked at vessels of ovary of a sweet-pea, and from 



this and other cases I believe that in the ovary the midrib 



vessel alone gives homologies, and that 



the vessels on the edge of the carpel leaf 



often run into the wrong bundle, just like 



those on the sides of the sepals. Hence 



I [suppose] in Crucifers that the ovarium 



consists of two pistils; A A [fig. 12] being 



the midrib vessels, and B B being those 



formed of the vessels on edges of the 



two carpels, run together, and going to 



wrong bundles. I came to this conclusion 



before receiving your letter. 



I wonder why Asa Gray will not believe in the quaternary 

 arrangement ; I had fancied that you saw some great diffi- 

 culty in the case, and that made me think that my notion 

 must be wrong. 



To J. D. Hooker. Letter 617 



Down, Sept. 2;th [1862]. 



Masdevallia turns out nothing wonderful ; x I was merely 

 stupid about it ; I am not the less obliged for its loan, for if 

 I had lived till 100 years old I should have been uneasy about 

 it. It shall be returned the first day I send to Bromley. I 

 have steamed the other plants, and made the sensitive plant 

 very sensitive, and shall soon try some experiments on it. 

 But after all it will only be amusement. Nevertheless, if not 

 causing too much trouble, I should be very glad of a few 

 young plants of this and Hedysarum 2 in summer, for this 

 kind of work takes no time and amuses me much. Have 

 you seeds of Oxalis sensitiva, which I see mentioned in books? 

 By the way, what a fault it is in Henslow's Botany that he 

 gives hardly any references ; he alludes to great series of 



1 This may refer to the homologies of the parts. He was unable 

 to understand the mechanism of the flower. Fertilisation of Orchids, 

 Ed. II., p. 136. 



2 Hedysarutn or Desinodium gyrans, the telegraph-plant. 

 VOL. II. 19 



