[115]

Radicle of Vicia faba, (1/2 natural scale) which had first grown vertically downwards. The bean was than laid on its side (L) during 1h. 35m, during which time the radicle was extended horizontally & was must have been acted on by geotropism though it remained quite straight. — The apex was then now cut off for a length of 1.5 mm & the radicle was again placed vertically downwards. After 24 h. the radicle was bent almost at right angles (at A) through the subsequent transmitted effect of geotropism.— After 3 d It then continued to grow out horizontally during 4! days from A B as owing to the absence of the tip it could was not be acted on by geotropism. After this interval a new tip was formed & now geotropism again acted on the it; & now it again grew almost vertically down, from B to C.