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of the pollinia by insects, including the movement of depression, are as perfect as in the species which depend upon insect aid." Hence there can be little doubt that this species is occasionally cross-fertilised.

Fig. 11.

Habenaria chlorantha, or Butterfly Orchis.

a a.	anther-cells.
d.	disc of pollinium.
s.	stigma.
n.	nectary.
n′.	orrifice of nectary.
l.	labellum.

A. Flower viewed in front, with all the sepals and petals removed except the labellum with its nectary, which is turned to one side.

B. A pollinium. (This has hardly a sufficiently elongated appearance.) The drum-like pedicel is hidden behind the disc.

C. Diagram, giving a section through the viscid disc, the drum-like pedicel, and the attached end of the caudicle. The viscid disc is formed of an upper membrane with a layer of viscid matter beneath.

Habenaria or Platanthera chlorantha.—The pollinia of the Large Butterfly Orchis differ considerably from those of any species hitherto mentioned. The two