542 



LECTURE XX. 



A. 



B. 



FIG. 59 (after Duchartre). A, leaf of Mimosa pudica in the diurnal position 

 B, in the nocturnal position. 



A. 



B. 



FIG. 60 (after Darwin). A, Leaves of Hedysarum (Desmodiuni) gyrans, in 

 the diurnal position; B, in the nocturnal position. 



