Page:Darwin - The various contrivances by which orchids are fertilized by insects (1877).djvu/159

substance. The large concave but shallow stigmatic surface is seated beneath the rostellum. The produced anterior lip of the anther (see A) almost entirely covers the upper surface of the rostellum. The fila-

Fig. 21.

Dendrobium chrysanthum.

Aa. anther.	As. stigma.
Ar. rostellum.	Al. labellum.
An. nectary.

A. Lateral view of flower, with the anther in its proper position, before the ejection of the pollinia. All the sepals and petals are removed except the labellum, which is longitudinally bisected.

B. Outline of column, viewed laterally, after the anther has ejected the pollinia.

C. Front view of column, showing the empty cells of the anther, after it has ejected its pollinia. The anther is represented hanging too low down, and covering more of the stigma than it really does.

ment of the anther is of considerable length, but is hidden in the side view, A, behind the middle of the anther; in the section, B, it is seen, after it has sprung forward: it is elastic, and presses the anther firmly down on the inclined surface of the clinan-