Ch. XVI] FERTILISATION OP FLOWERS. 305 



only seen pollen of a Cattleya on a bee, but surely have you 

 not unintentionally sent me what I wanted most (after Catase- 

 tum or Mormodes), viz., one of the Epidendrea ? ! I particu- 

 larly want (and will presently tell you why) another spike of this 

 little Orchid, with older flowers, some even almost withered." 



His delight in observation is again shown in a letter to 

 Dr. Gray (1863). Referring to Criiger's letters from Trinidad, 

 he wrote : — " Happy man, he has actually seen crowds of 

 bees flying round Catasetum, with the pollinia sticking to their 

 backs ! " 



The following extracts of letters to Sir J. D. Hooker illus- 

 trate 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. 1 would give a 

 good deal to know what the rostelluin is, of which I have 

 traced so many curious modifications. I suppose it cannot 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 I The beauty of the adaptation of parts seems to m« 

 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 curious 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 fewness, 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 ; 



* It is a modification of the upper stigma, 

 t This rather obscure statement may be paraphrased thus : — 

 The machinery is bo 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 

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



X 



