Chap IV. CIECUMNUTATION OF STOLONS. 217 



from side to side as up and down ; and differed in this- respect 

 remarkably from the movement in the previous cases. During 

 the latter part of the day, viz., between 3 and 10.30 p.m., the 



Fig. 87. 



'iattm 



raop.m 

 -s'pan. 



Fraga'-in: circumnvitation of another and younger stolon, traced from 

 8 A.M. to 10.30 P.M. Figure reduced to one-half of original scale. 



actual distance travelled by the apex amounted to 1'15 inch ; 

 and in the course of the whole day to at least 2'67 inch. This 

 is an amount of movement almost comparable with that of 

 some climbing plants. The same stolon was observed on the 

 following day, and now it moved in a somewhat less complex 

 manner, in a plane not far from vertical. The extreme amount 

 of actual movement was 1'55 inch in one direction, and "6 inch 

 in another direction at right angles. During neither of these 

 days did the stolon bend downwards through geotropism or its 

 own weight. 



Four stolons still attached to the plant were laid on damp 

 sand in the back of a room, with their tips facing the north-east 

 windows. They were thus placed because De Vries says * that 

 they are apheliotropic when exposed to the light of the sun ; hut 

 we could not perceive any effect from the above feeble degree of 

 illumination. We may add that on another occasion, late in the 

 summer, some stolons, placed upright before a south-west window 



' Arbciten Bot. Inst., Wurzburg,' 1872, p. 434. 



