234 



CIECUMNUTATION OF LEAVES. 



Chap. IV 



As tlic evening rise and the early morning fall were ■anusually 

 large, the angle of the petiole above the horizon was measured 

 at the two periods, and the leaf was found to have risen 19' 



Fig. 100. 



ns' 



■«?4J'fl.OT.4* 



Vieia faba ; circumnutation of leaf, traced from 7.15 P.M. July 2nd tc 

 10.15 A.M. 4th. Apex of the two terminal leaflets 7J inches from th« 

 vertical glass. Figure here reduced to two-thirds of original scale. 

 Temp. 17°-18° C. 



between 12.20 p.m. and 10.45 p.m., and to have fallen 23° 30' 



between the latter hour and 10.20 a.m. on the following morning. 



The main petiole was now secured to a stick close to the base 



