POSITION OF COTTON LEAVES AT NIGHT 



The leaves of the cotton plant perform definite movements in reaction to light. These 

 movements are controlled by two organs located on the petiole of the leaf: one, the pulvinus at the 

 base of the petiole, and the other, the pulvinus at the distal or outer end of the same. The 

 above photograph shows the jjosition which the leaves assume at night: though they have the 

 appearance of being wilted, the turgidity is actually greater than it is when the leaves are in the 

 day position. (Fig. 8.j 



