Note 14 — Chapter IV · THE CIRCUMNUTATING MOVEMENTS OF THE SEVERAL PARTS OF MATURE PLANTS. (continued 2)

Mr. Loomis and Prof. Asa Gray have described (‘Botanical Gazette,’ 1880, pp. 27, 43), an extremely curious case of movement in the fronds, but only in the fruiting fronds, of Asplenium trichomanes. They move almost as rapidly as the little leaflets of Desmodium gyrans, alternately backwards and forwards through from 20 to 40 degrees, in a plane at right angles to that of the frond. The apex of the frond describes “a long and very narrow ellipse,” so that it circumnutates. But the movement differs from ordinary circumnutation as it occurs only when the plant is exposed to the light; even artificial light “is sufficient to excite motion for a few minutes.”