CHAP. I. 



BRASSICA. 



17 



placed that a line joining the two cotyledons pointed towards 

 the window ; and the filament was attached to the smaller Coty- 

 ledon on the side furthest from the window. Moreover, the 

 plant was now for the first time placed in this position. The 

 cotyledons bowed themselves greatly towards the light from 8 to 

 10.50 A.M., when the first dot was made (Fig. 7). During the 



Fig. 7. 



Brassica oleracea : conjoint circumnutation of the hypocotyl and cotyledons, 

 from 10.50 A.M. to 8 A.M. on the following morning. Tracing made 

 on a vertical glass. 



next 12 hours the bead swept obliquely up and down 8 times 

 and described 4 figures representing ellipses ; so that it travelled 

 at nearly the same rate as in the previous case. During the 

 night it moved upwards, owing to the sleep-movement of the 

 cotyledons, and continued to move in the same direction till 

 9 A.M. on the following morning ; but this latter movement 

 would not have occurred with seedlings under their natural 

 conditions fully exposed to the light. 

 By 9.25 A.M. on this second day the same cotyledon had 



