excitement which causes the disc to separate from the surrounding parts, include some made on the following species. Several flowers were sent me by post and by the railroad, and must have been much jarred, but they had not exploded. I let two flowers fall from a height of two or three inches on the table, but the pollinia were not ejected. I cut off with a crash with a pair of scissors the thick labellum and ovarium close beneath the flower; but this violence produced no effect. Nor did deep pricks in various parts of the column, even within the stigmatic chamber. A blow, sufficiently hard to knock off the anther, causes the ejection of the pollinium, as occurred to me once by accident. Twice I pressed rather hard on the pedicel, and consequently on the underlying rostellum, without any effect. Whilst pressing on the pedicel, I gently removed the anther, and then the pollen-bearing end of the pollinium sprang up from its elasticity, and this movement caused the disc to separate. M. Ménière,[1] however, states that the anther-case sometimes detaches itself, or can be gently detached, without the disc separating; and that then the upper end of the pedicel, bearing the pollen-masses, swings downwards in front of the stigmatic chamber.
After trials made on fifteen flowers of three species, I find that no moderate degree of violence on any part of the flower, except on the antennæ, produces any effect. But when the left-hand antenna of C. saccatum, or either antenna of the three following species, is touched, the pollinium is instantly ejected. The extreme tip and the whole length of the antennæ are sensitive. In one specimen of C. tridentatum a touch from a bristle sufficed; in five specimens of
- ↑ 'Bull, de la Soc. Bot. de France,' tom. i. 1854, p. 367.
