Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/78

58 supply of seed; and we have seen with the other British species of Ophrys which cannot fertilise themselves, how small a proportion of their flowers produce capsules. Judging therefore from the structure of the flowers of O. apifera, it seems almost certain that at some former period they were adapted for cross-fertilisation, but that failing to produce a sufficiency of seed they became slightly modified so as to fertilise themselves. It is, however, remarkable on this view, that none of the parts in question show any tendency to abortion—that in the several and distant countries which the plant inhabits, the flowers are still conspicuous, the discs still viscid, and the caudicles still retain the power of movement when the discs are exposed to the air. The metallic points at the base of the labellum are however smaller than in the other species; and if these serve to attract insects, this difference is of some signification. As it can hardly be doubted that O. apifera was at first constructed so as to be regularly cross-fertilised, it may be asked will it ever revert to its former state; and if it does not so revert, will it become extinct? These questions cannot be answered, any more than in the case of those plants which are now propagated exclusively by buds, stolons, &c., but which produce flowers that rarely or never set any seed; and there is reason to believe that a sexual propagation is closely analogous to long-continued self-fertilisation.

Finally Mr. Moggridge has shown that in North Italy Ophrys apifera, aranifera, arachnites, and scolopax are connected by so many and such close intermediate links, that all seem to form a single species in