Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/120

100 blunt, solid, upper end of the anther, thus freeing the pollen-masses. Various other insects besides hive-bees visit the flowers. My son saw several large flies (Sarcophaga carnosa) haunting them; but they did not enter in so neat and regular a manner as the hive-bees; nevertheless two had pollen-masses attached to their foreheads. Several smaller flies (Cœlopa frigida) were also seen entering and leaving the flowers, with pollen-masses adhering rather irregularly to the dorsal surface of the thorax. Three or four distinct kinds of Hymenoptera (one of small size being Crabro brevis) likewise visited the flowers; and three of these Hymenoptera had pollen-masses attached to their backs. Other still more minute Diptera, Coleoptera, and ants were seen sucking the nectar; but these insects appeared to be too small to transport the pollen-masses. It is remarkable that some of the foregoing insects should visit the flowers; for Mr. F. Walker informs me that the Sarcophaga frequents decaying animal matter, and the Cœlopa haunts seaweed, occasionally settling on flowers. The Crabro also, as I hear from Mr. F. Smith, collects small beetles (Haticæ) for provisioning its nest. It is equally remarkable, seeing how many kinds of insects visit this Epipactis, that although my son watched hundreds of plants for some hours on three occasions, not a single humble-bee alighted on a flower, though many were flying about.

Epipactis latifolia.—This species agrees with the last in most respects. The rostellum, however, projects considerably further beyond the face of the stigma, and the blunt upper end of the anther less so. The viscid matter lining the elastic cap of the rostellum takes a longer time to get dry. The upper petals and sepals are more widely expanded than in E. palustris: the distal portion of the labellum is smaller, and is