DARWINISM 



STATED BY DAKWIN HIMSELF. 



I. 



THE MOVEMENTS AND HABITS OF PLANTS. 



Tlie Power The most widely_prevalent movement is 



in Plants essentially of the same nature as that of the 

 page 1. stem of a climbing plant, which bends suc- 

 cessively to all points of the compass, so that the tip 

 revolves. This movement has been called by Sachs "re- 

 volving nutation " ; but we have found it much more 

 convenient to use the terms circumnutation and cir- 

 cumnutate. As we shall have to say much about this 

 movement, it will be useful here briefly to describe its 

 nature. If we observe a circumnutating stem, which 

 happens at the time to be bent, we will say toward the 

 north, it will be found gradually to bend more and more 

 easterly, until it ^faces the east ; and so onward to the 

 south, then to the west, and back again to the north. If 

 the movement had been quite regular, the apex would 

 have described a circle, or rather,. as the stem is always 

 growing upward, a circular spiral. But it generally de- 

 scribes irregular elliptical or oval figures ; for the apex, 

 after pointing in any one direction, commonly moves 

 back to the opposite side, not, however, returning along 



