[pages 153-4]

A CORRESPONDENCE WITH MR. DARWIN.

(1860-1862.)

At this time [June 1860] he had an interesting correspondence with Mr. Darwin about orchids. Mr. Darwin, in his study of orchid fertilization, encountered from the first a troublesome stumbling-block in the Bee Orchis (Ophrys apifera). Of the twelve kinds which grew in the neighborhood of his Kentish home, eleven, in different ways, perfectly fitted his view of the adaptation of their structures to cross-fertilization by insects. But the "Bee," with a structure as beautiful and complicated as any, alone seemed to be visited by no insect, yet to form seed. Unwilling to think that so highly developed a plant could be quite independent of insect agency, Mr. Darwin became very anxious to have specimens examined in other parts of the country where it was more plentiful than at Down, and therefore, he thought, more likely to attract notice from nectar-seeking insects. This desire led him to consult Mr. [Hewett Cottrell] Watson, by whose advice Mr. More was applied to.

Mr. Darwin's first letter to Mr. More is dated June 24th, 1860:

"Dear Sir: I hope that you will forgive the liberty which I take in writing to you and requesting a favor. Mr. H. C. Watson has given me your address, and has told me that he thought that you would be willing to oblige me. Will you please to read the enclosed; and then you will understand what I wish observed with respect to the bee orchis. What I especially wish, from information which I have received since publishing the enclosed, is that the state of the pollen-masses should be noted in flowers just beginning to wither, in a district where the bee orchis is extremely common. I have been assured that in part of the Isle of Wight, viz. Freshwater Gate, numbers occur, almost crowded together. Whether anything of this kind occurs in your vicinity I know not; but if in your power, I should be infinitely obliged for any information. As I am writing, I will venture to mention another wish 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 really 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 arrangement of the first species sent him in response to his application, which happened to be Epipactis palustris. "You can hardly imagine (he wrote) what an interesting morning'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 "Fertilisation 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, via 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.

Alexander Goodman More (1830-1895), English botanist.