[223]

Iris pseudo-acorus

1878

May 28-29 young leaf 13 inches high above water, with 2 triangles of paper gummed one beneath another on at right angle to apex, horizontal glass 12 inches above. Under Skylight movement not sufficiently magnified.

Day rather cold 15° to 16° Cent.—  See tracing.— Between 6° 40 & 2° on 29' zig-zagged; After 2° on 29th until 11° P.m. continued to make little made 2 little additional circles, for the point came back to the lower side in Tracing.—   There can be no doubt that leaf circumnutates on a small scale.—

The arc of a youngleaf, which rising 13 inches above the water in which plant, grew, was is was traced during 27h. 30m during 36hr, but in the figure given (Fig.) It manifestly circumnutated. But On the second morning between 6° 40' am & 2° P.m the apex changed its course five times, & in the next 8h 40m, it zig-zagged, making 2 small ellipses, to the lower side of the figure as here given; but to have added these tracing after 2 P.m lines wd have rendered the fig too complicated.