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 stem 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 circwnnutation. 

 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 cii'cle, 

 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 arc successively described, with their longer 



