Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/74

54 the experiment was superfluous, I covered up a plant under a net, so that the wind, but no insects, could pass in, and in a few days the pollinia became attached to the stigmas. But the pollinia of a spike kept in water in a still room remained free, suspended in front of the stigma, until the flowers withered.

Robert Brown first observed that the structure of the Bee Ophrys is adapted for self-fertilisation. When we consider the unusual and perfectly-adapted length, as well as the remarkable flexibility of the caudicles; when we see that the anther-cells naturally open, and that the masses of pollen, from their weight, slowly fall down to the exact level of the stigmatic surface, and are there made to vibrate by the slightest breath of wind until the stigma is struck; it is impossible to doubt that these several points of structure and function, which occur in no other British Orchid, are specially adapted for self-fertilisation.

The result is what might have been anticipated. I have often noticed that the spikes of the Bee Ophrys apparently produced as many seed-capsules as flowers; and near Torquay I carefully examined many dozen plants, some time after the flowering season; and on all I found from one to four, and occasionally five, fine capsules, that is, as many capsules as there had been flowers. In extremely few cases, with the exception of a few deformities, generally on the summit of the spike, could a flower be found which had not produced a capsule. Let it be observed what a contrast this species presents with the Fly Ophrys, which requires insect aid for its fertilisation, and which from forty-nine flowers produced only seven capsules!