26 



BOTANICAL GAZETTE 



[JANUARY 



cm. long, were selected for these 



and the 



2 



nodes 



Straight stems, 

 experiments. The 

 removed, the pieces chosen for experimentation containing about 

 4-7 or 8 nodes. Each stem was suspended horizontally by 2 

 threads (fig. 1), one at each end, in a jar the bottom of which was 

 filled with water. 



The jar was loosely 



wi 



so that the stems were surrounded by an atmosphere almost com 

 pletely saturated with water vapor* 





Fig. i 



their growin 



her surprised to find that stems deprived of 

 should show geotropic curvatures. These 



curv 



(%. 1) 



the stem, both nodes and internodes, bent 



We shall see later that the bending was accom 



an increase in the length of the 



the 



stem, while the upper side of the stem 

 quence of this growth. 



