Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/284

264 developed state, of Goodyera, Epipactis, and Spiranthes, all members of the Neotteæ, could by further slight modifications have given birth to the tribe of the Ophreæ.

Hardly any question in Natural History is more vague and difficult to answer than what forms ought to be considered as the highest in a large group; for all are well adapted to their conditions of life. If we look to successive modifications, with differentiation of parts and consequent complexity of structure, as the standard of comparison, the Ophreæ and Vandeæ will stand the highest among the Orchideæ. Are we to lay much stress on the size and beauty of the flower, and on the size of the whole plant? if so, the Vandeæ are pre-eminent. They, have, also, rather more complex pollinia, with the pollen-masses often reduced to two. The rostellum, on the other hand, has apparently been more modified from its primordial stigmatic nature in the Ophreæ, than in the Vandeæ. In the Ophreæ the stamens of the inner whorl are almost entirely suppressed,—the auricles—mere rudiments of rudiments—being alone retained; and even these are sometimes lost. These stamens, therefore, have suffered extreme reduction; but can this be considered as a sign of highness? I should doubt whether any member of the Orchidean order has been more profoundly modified in its whole structure than Bonatea spedosa, one of the Ophreæ. So again, within this same tribe, nothing can be more perfect than the contrivances in Orchis pyramidalis for its fertilisation. Yet an ill-defined feeling tells me to rank the magnificent Vandese as the highest. When we look within this tribe at the