Ill 



THE MOVEMENTS OF PLANTS ^ 



It is sometimes asserted that the power of move- 

 ment is a character distinguishing animals from 

 plants. This statement arises to some extent from 

 an obvious confusion of thought. Trees are 

 stationary, they are rooted to one spot, but they are 

 not therefore motionless. We think them so 

 because our eyes are dull — a fault curable with the 

 help of a microscope. And when we get into the 

 land of magnification, where the little looks big 

 and the slow looks quick, we see such evidence of 

 movement that we wonder not to hear as well 

 as see the stream of life that flows before our eyes. 



In speaking of the cells of which plants are 

 built, Huxley said that a plant is "an animal 

 enclosed in a wooden box." It is this prisoner, the 

 living protoplasm, that we may watch pacing round 

 its prison walls. And we may see it stop as though 

 frightened at our rough usage, and then, after a 

 hesitating twitch or two, we see it recover and once 

 more flow round the cell. Or we can watch under the 

 microscope minute free-swimming plants rushing 

 across the field of view, all one way, Hke a flock of 

 little green sheep that we can drive to and fro with 

 a ray of light for a sheep-dog. 



* Evening lecture delivered at the Glasgow meeting of the 

 British Association, September i6, igoi. Reprinted with altera- 

 tions, from Nature, November 14, 1901. 



36 



