162 



UNEQUAL TURGESCKNCE. 



[CH. VII 



Fig. 31 1 which represents bean-roots with cards attached, 

 and showing various degrees of curvature. 



Fia. 31. Exp. 207. 



(208) Giesiel ski's eccperimentK 



This experiment is of interest in relation to the 

 mechanism of growth curvatures because it shows that 

 curvatures might conceivably arise through unequal 

 turgescence of the two sides of a plant-member. 



Take a germinating bean with rather a long root, say 

 40 — 45 mm., and let it lie on the table for a minute 



' Fower of Movement, fig. 65, p. 134. 



^ Sachs (Arbeiten, i. p. 219) quotes Ciesielski's work as appearing in 

 his Breslau Dissertation, 1871. 



