2S 



BOTANICAL GAZETTE 



[JANUARY 



hand in the photograph are 6 stems havin 



the apex, 

 reached < 

 the base. 



stems 



stems having 



this case the curvature is generallv much 



/ 



/ 



/ 



* 



/ 



Fig. 4 



when the leaf is at the apex. Both groups of stems had been sus- 

 pended horizontally and both had been put into the jar at the same 

 time. The photograph was taken on the eleventh day. This 

 experiment also is always successful. 



