THE GENERAL CHEMISTRY AND PHYSICS OF PLANT-LIFE. 285 



hasten or favor the twining about the support. The amount of 

 true antidromic torsion influences in a high degree the mobility 

 of the internodes, so that the amplitude of the movements of 

 nutation decreases with the increase of antidromic torsion. 

 (Within certain limits the amount of true torsion increases as 

 the thickness of the support increases. Apparent torsion in- 

 creases with the closeness of the spirals.) 



ScHWENDENER has demonstrated that by eliminating the 

 weight of the overhanging stem-apex twining is not in any way 

 disturbed, which proves that the weight of the plant is not an 

 essential factor in the process of twining. 



