1862] Experiments "with Epipactis palustr is. 157 



you take much trouble to try this : but if I had the oppor- 

 tunity I should try it for bare chance of its showing that 

 the terminal portion of labellum was of use, as I suspect, in 

 guiding and aiding some unknown insect in its proper 

 function of fertilising the flower." 



The "little experiment" was tried this year on two 

 flowers only, for nearly all had already expanded. The 

 result is described (in a foot-note) at page 101 of Mr. Dar- 

 win's book : 



As it is quite possible that I may have overrated the importance of 

 the peculiar structure of the labellum, I asked Mr. A. G. More to re- 

 move the distal portion of the labellum of some flowers before they had 

 expanded, but I was too late in my application. He was able to try only 

 two flowers which were situated near the summit of the spike. These 

 flowers formed seed capsules which were certainly small ; but this may 

 have been owing to their position. Unfortunately also these capsules 

 shed most of their seed in being sent to me, so that I could not ascer- 

 tain whether the seeds were well formed. Of the few seeds which did 

 remain within these two capsules many were shrivelled and bad. 



The doubtfulness of these results was the more disap- 

 pointing, as the book on Orchids was ready to go to press, 

 and was published soon after, in the winter of 1861-2. But 

 still the subject had not lost its fascination for Mr. Darwin, 

 who, in 1862, requested a repetition of the experiment. This 

 time it was tried on nine flowers ; and the upshot is best 

 described in Mr. Darwin's letter to Mr. More, Sept. 26th, 

 1862 : 



MY DEAR SIR, I thank you cordially for the specimens received this 

 morning, and for all the trouble which you have so kindly taken. Put- 

 ting on one side the three imperfect capsules, six are left, of which the 

 labellum had been removed. In comparison with the five naturally fer- 

 tilised capsules, two of the mutilated produced as much seed, and 

 seemed to have been fully fertilised ; the four others produced very 

 much less seed. So that the result in a limited degree supports my 

 belief in use of labellum, but 1 can now see that a dozen other capsules 

 from mutilated flowers ought to be compared with a dozen naturally fer- 

 tilised. But tljis would not be worth your time and trouble. 



Further experiments in 1863 were intended. "I am 

 ashamed to say so, but if you are in the Isle of Wight I 



