Stimulation and Correlation. 



"5 



125. Perceptive region in leaves of grasses Grow 



a number of seedlings of oats or wheat or canary grass 



Fig. 84. — Positions assumed by blades of leaves of mallow. The arrows denote 

 direction of rays of light. 



[Fhalaris) in a shallow dish of moist soil or sawdust. Make 

 several cylinders of tin-foil of sufficient size to fit snugly over 

 the leaves. To do this, wrap a strip of tin-foil round a match 



