THE MOVEMENTS OF PLANTS. 



INTRODUCTION. 



THE chief object of the present work is to describe 

 and connect together several large classes of move- 

 ment, common to almost all plants. The most widely 

 prevalent movement is essentially of the same nature 

 as that of the stern of a climbing plant, which bends 

 successively to all points of the compass, so that the 

 tip revolves. This movement has been called by 

 Sachs " revolving nutation ;" but we have found it 

 much more convenient to use the terms circumnutation 

 and circumnutate. 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 towards the north, it will be found gradually to 

 bend more and more easterly, until it faces the east ; 

 and so onwards 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 upwards, a 

 circular spiral. But it generally describes irregular 

 elliptical or oval figures ; for the apex, after point- 

 ing in any one direction, commonly moves back 

 to the opposite side, not, however, returning along 

 the same line. Afterwards other irregular ellipses 

 or ovals are successively described, with their longer 



