324: BOTANY. [ch. xvi. 



illustrate further the interest which his work excited in 

 him: 



" Veitch sent me a grand lot this morning. What 

 wonderful structures ! 



" I have now seen enough, and you must not send me 

 more, for though I enjoy looking at them much, and it has 

 been very useful to me, seeing so many different forms, it is 

 idleness. For my object each species requires studying for 

 days. I wish you had time to take up the group. I would 

 give a good deal to know what the rostellum is, of which I 

 have traced so many curious modifications. I suppose it can- 

 not be one of the stigmas,* there seems a great tendency for 

 two lateral stigmas to appear. My paper, though touching 

 on only subordinate points will run, I fear, to 100 MS. folio 

 pages ! The beauty of the adaptation of parts seems to me 

 unparalleled. I should think or guess waxy pollen was most 

 differentiated. In Cypripedium which seems least modified, 

 and a much exterminated group, the grains are single. In 

 all others, as far as I have seen, they are in packets of four ; 

 and these packets cohere into many wedge-formed masses 

 in Orchis ; into eight, four, and finally two. It seems curi- 

 ous that a flower should exist, which could at most fertilise 

 only two other flowers, seeing how abundant pollen generally 

 is ; this fact I look at as explaining the perfection of the 

 contrivance by which the pollen, so important from its few- 

 ness, is carried from flower to flower "f (1861). 



" I was thinking of writing to you to-day, when your 

 note with the Orchids came. What frightful trouble you 

 have taken about Vanilla ; you really must not take an atom 

 more ; for the Orchids are more play than real work. I 

 have been much interested by Epidendrum, and have worked 

 all morning at them ; for Heaven's sake, do not corrupt me 

 by any more" (August 30, 1861). 



He originally intended to publish his notes on Orchids 

 as a paper in the Linnean Society's Journal, but it soon be- 

 came evident that a separate volume would be a more suit- 

 able form of publication. In a letter to Sir J. D. Hooker, 

 Sept. 24, 1861, he writes : 



* It is a modification of the upper stigma, 

 t This rather obscure statement may be paraphrased thus : 

 The machinery is so perfect that the plant can afford to minimise the 

 amount of pollen produced. Where the machinery for pollen distribution is 

 of a cruder sort, for instance where it is carried by the wind, enormous quan- 

 tities are produced, e. g. in the fir tree. 



