account of my own health and that of my daughter, I shall be on the move for the next two or three weeks. I am sure I have much cause to apologise for the liberty which I have taken... LETTER 595. TO A.G. MORE. Down, August 3rd, 1860. I thank you most sincerely for sending me the Epipactis [palustris]. You can hardly imagine what an interesting morning's work you have given me, as the rostellum exhibited a quite new modification of structure. It has been extremely kind of you to take so very much trouble for me. Have you looked at the pollen-masses of the bee-Ophrys? I do not know whether the Epipactis grows near to your house: if it does, and any object takes you to the place (pray do not for a moment think me so very unreasonable as to ask you to go on purpose), would you be so kind [as] to watch the flowers for a quarter of an hour, and mark whether any insects (and what?) visit these flowers. I should suppose they would crawl in by depressing the terminal portion of the labellum; and that when within the flower this terminal portion would resume its former position; and lastly, that the insect in crawling out would not depress the labellum, but would crawl out at back of flower. (595/1. The observations of Mr. William Darwin on Epipactis palustris given in the "Fertilisation of Orchids," Edition II., 1877, page 99, bear on this point. The chief fertilisers are hive-bees, which are too big to crawl into the flower. They cling to the labellum, and by depressing it open up the entrance to the flower. Owing to the elasticity of the labellum and its consequent tendency to spring up when released, the bees, "as they left the flower, seemed to fly rather upwards." This agrees with Darwin's conception of the mechanism of the flower as given in the first edition of the Orchid book, 1862, page 100, although at that time he imagined that the fertilising insect crawled into the flower. The extreme flexibility and elasticity of the labellum was first observed by Mr. More (see first edition, page 99). The description of the flower given in the above letter to Mr. More is not quite clear; the reader is referred to the "Fertilisation of Orchids," loc. cit.) An insect crawling out of a recently opened flower would, I believe, have parts of the pollen-masses adhering to the back or shoulder. I have seen this in Listera. How I should like to watch the Epipactis. If you can it any time send me Spiranthes or Aceras or O. ustulata, you would complete your work of kindness.