216 



CIRCUMNUTATION OF STOLONS. CHAP. IV. 



Fig. 86. 



lateral deflection. The first and last dots made on this second 

 day, viz., at 7 A.M. and 11 P.M., were close together, showing* 

 that the stolon had not fallen or risen. Nevertheless, by com- 

 paring its position on 

 the morning of the 19th 

 and 21st, it is obvious 

 that the stolon had sunk ; 

 and this may be attri- 

 buted to slow bending 

 down either from its own 

 weight or from geotro- 

 pism. 



During a part of the 20th 

 an orthogonal tracing was 

 made by applying a cube 

 of wood to the vertical 

 glass and bringing the 

 apex of the stolon at suc- 

 cessive periods into a line 

 with one edge; a dot 

 being made each time on 

 the glass. This tracing 

 therefore represented very 

 nearly the actual amount 

 of movement of the apex ; 

 and in the course of 9 h. 

 the distance of the ex- 

 treme dots from one an- 

 other was '45 inch. By 

 the same method it was 

 ascertained that the apex 

 moved between 7 A.M. on 

 8>a.m.21? the 20th and 8 A.M. on the 



Fragaria : circumnutation of the same stolon 21st a distance of "82 inch, 

 as in the last figure, observed in the same A younger an d shorter 



^ stolon was supported so 

 that it projected at about 

 45 above the horizon, and its movement was traced by the 

 same orthogonal method. On the first day the apex soon 

 rose above the field of vision. By the next morning it had 

 sunk, and the course pursued was now traced during 14 h. 

 30 m. (Fig. 87). The amount of movement was almost the same, 



