Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/100

80

ARETHUSEÆ.

Cephalanthera grandiflora.—This Orchid is remarkable from not possessing a rostellum, which is so eminently characteristic of the order. The stigma is large, and the anther stands above it. The pollen is extremely friable and readily adheres to any object. The grains are tied together by a few weak elastic threads; but they are not cemented together, so as to form compound pollen-grains, as in almost all other Orchids. In this latter character and in the complete abortion of the rostellum we have evidence of degradation; and Cephalanthera appears to me like a degraded Epipactis, a member of the Neotteæ, to be described in the next chapter.

The anther opens whilst the flower is in bud and partly expels the pollen, which stands in two nearly free upright pillars, each nearly divided longitudinally into halves. These subdivided pillars rest against or even overhang the upper square edge of the stigma, which rises to about one-third of their height (see front