DARWINISM 



STATED BY DARWIN HIMSELF. 



L 

 THE MOVEMENTS AND HABITS OF PLANTS. 



The Power The most widely prevalent movement is 

 in Plan™ 611 essentially of the same nature as that of the 

 page l. 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 drcumnutation 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 



