[281]

March 7th–11th 1878

Plumbago Capensis

A small lateral branch, projecting standing about 35° above the horizon & growing freely was selected for observation & some of the upper branches having been cut away, a filament was fixed transversely across it near its summit tip, & the movement of the bead traced on Horizontal glass.— Plant illuminated very feebly from above.

Tracing magnified 13 times. The branches never showed any tendency to turn upwards from apogeotropism; but for For the first 11 hours it moved to a great distance greatly in a nearly straight line to one side from some another cause ; probably owing probably to its having been deflected by the light whilst standing in Greenhouse, had been drawn to one opposite side by light. At 7° 20' P.m on March 7' a fresh tracing was began & continued during (see fig) & for about 2 hours it followed nearly same course, then & then bent to oth changed its course it a little; & during the night it changed its course completely, & moved at nearly right angle to its former direction. Next day (March 8th) one zig-zagged greatly, & so it did the following day (9th) till about 3° P.m by which time so the tracing figure had become so complicated a figure had been was described that it could hardly be copied accurately. & no more dots were made. But It continued moving to mo in the same manner round & round over a small space during during the whole of the 10th & morning of the 11th turn round & round over the same small circular space — The movement was small for the spaces swept in a sl moving line over repeatedly between 3° P.m on the 9th to the early morning of the 11th was a circle of only 1/26th (.038) of an inch in diameter, & the tracing ought to have been magnified thrice as much for the movements of the bead to have been accurately followed; but from the zig-zag line previously formed & the figure described, the stem no doubt circumnutated.—

For tables of times see old M. S with Pelargonium.