Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/298

278 children of a single plant would nearly (in the ratio of 47 to 50) clothe with one uniform green carpet the entire surface of the land throughout the globe. But the number of seeds produced by one of our common British orchids is as nothing compared to that of some of the exotic kinds. Mr. Scott found that the capsule of an Acropera contained 371,250 seeds; and judging from the number of flowers, a single plant would sometimes yield about seventy-four millions of seeds. Fritz Müller found 1,756,440 seeds in a single capsule of a Maxillaria; and the same plant sometimes bore half-a-dozen such capsules. I may add that by counting the packets of pollen (one of which was broken up under the microscope) I estimated that the number of pollen-grains, each of which emits its tube, in a single anther of Orchis mascula was 122,400. Amici estimated the number in O. morio at 120,300. As these two species apparently do not produce more seed than the allied O. maculata, a capsule of which contained 6200 seeds, we see that there are about twenty pollen-grains for each ovule. According to this standard, the number of pollen-grains in the anther of a single flower of the Maxillaria which yielded 1,756,440 seeds must be prodigious.

What checks the unlimited multiplication of the Orchideæ throughout the world is not known. The minute seeds within their light coats are well fitted for wide dissemination; and I have several times observed seedlings springing up in my orchard and in a newly-planted wood, which must have come from a considerable distance. This was especially the case with Epipactis latifolia; and an instance has been recorded by a good observer of seedlings of this plant