Page:Popular Science Monthly Volume 18.djvu/523

Rh leaflets, as seen in Fig. 9, with its lower surface fully exposed to the zenith.

The nyctitropic movements of ten species of the lotus tribe were observed and found to be alike. The main petiole rises a little at night, and the three leaflets rise till they become vertical, and at the



same time approach each other. In most of the species the leaflets rise so much as to press against the stem, and not rarely they become inclined a little inward, with their lower surfaces exposed obliquely to the zenith. The young leaves on the summits of the stems close up at night so much as often to resemble large buds. The stipule-like leaflets,



which are often of large size, rise up like the other leaflets, and press against the stem (see Fig. 10). The circumnutation of a terminal leaflet (with the stem secured) was traced during two days, but the