More Letters Of Charles Darwin Volume 2 A Record Of His Work In
Chapter 360
I must write a line to cry peccavi. I have seen the action in Ophrys exactly as you describe, and am thoroughly ashamed of my inaccuracy. (695/1. See "Fertilisation of Orchids," Edition II., page 46, where Lord Farrer's observations on the movement of the pollinia in Ophrys muscifera are given.) I find that the pollinia do not move if kept in a very damp atmosphere under a glass; so that it is just possible, though very improbable, that I may have observed them during a very damp day.
I am not much surprised that I overlooked the movement in Habenaria, as it takes so long. (695/2. This refers to Peristylus viridis, sometimes known as Habenaria viridis. Lord Farrer's observations are given in "Fertilisation of Orchids," Edition II., page 63.)
I am glad you have seen Listera; it requires to be seen to believe in the co-ordination in the position of the parts, the irritability, and the chemical nature of the viscid fluid. This reminds me that I carefully described to Huxley the shooting out of the pollinia in Catasetum, and received for an answer, "Do you really think that I can believe all that!" (695/3. See Letter 665.)