154 Alexander Goodman More. [i860 



which I have, namely, to examine fresh flowers and buds of the 

 Aceras, Spiranthes, Marsh Epipactis, and any other rare orchis. The 

 point which I wish to examine is itself very curious, but it would take 

 too long space to explain. Could you oblige me by taking the great 

 trouble to send me, in an old tin canister, any of the orchids ; it would 

 be a great kindness, but perhaps I am unreasonable to make such a 

 request. 



The point which Mr. Darwin here thought would take 

 too much explanation was probably his idea that in some 

 of the orchids mentioned the labella might be irritable. 

 He was quite taken by surprise with the actual arrange- 

 ment of the first species sent him in response to his appli- 

 cation, which happened to be Epipactis palustris. "You 

 can hardly imagine (he wrote) what an interesting morn- 

 ing's work you have given me, as the rostellum exhibited 

 a quite new modification of structure" (August 3rd, 1860). 

 The results of that " interesting morning's work" are set 

 forth at page 99 of Mr. Darwin's book on the " Fertilisa- 

 tion of Orchids," where it may be seen how largely the 

 domestic economy of the flower is thought by the author 

 to depend on a little circumstance described for him from 

 growing specimens by Mr. More the very delicate hinging 

 of the flap (or "distal portion") of the segment of the 

 flower called the labellum. " So flexible and elastic is the 

 hinge (between the two halves of the labellum) that the 

 weight of even a fly, as Mr. More informs me, depresses the 

 distal portion ; but when the weight is removed it instantly 

 springs up to its former and ordinary position, and with its 

 curious medial ridge partly closes the entrance into the 

 flower." The use of this mechanism, Mr. Darwin at once 

 concluded, was to enable an insect readily to crawl in, 

 ma the yielding labellum, and then, since the door behind 

 it instantly closes, to cause the insect to crawl out another 

 way upwards, and thereby detach the pollen-masses for 

 the benefit of the next flower visited. 



It was one thing, however, to have arrived at so clear 

 and satisfactory &prima facie hypothesis, and quite another 

 to get its truth confirmed by the insects as the teaching 

 of three successive summers was to show. 



Mr. Darwin was full of eagerness to test his conclu- 



