50 VIGNETTE $ FROM INVISIBLE LIFE. 



The whole compound organism, rolling and re- 

 volving in the water, forms a picture which once 

 seen is never forgotten. 



We call them plants, for they are mostly green, 

 and have but few of the characteristics of animal 

 life. "Yet," you say, "they move." Yes, they 

 are motile plants ; and if examined a little moro 

 closely, are seen to be covered with fine cilia, 

 or hairs, which by their vibrating action are sup- 

 posed to be the cause of the revolving motion 

 observable. We have probably here a promi- 

 nent instance of the active agency of sunlight 

 on the vegetable world. These special forms not 

 being attached to the earth, or, indeed, to anything 

 whatever, but only suspended, as it were, in a 

 medium which by its elasticity does not offer suffi- 

 cient resistance to keep it in one position and this 

 aided by the peculiar globular form of the plant 

 and its hair-like appendages the sunlight, which 

 in other fixed and stable forms produces an expan- 

 sion of growth, is here partially expended in pro- 

 ducing this revolving motion. 



It is a matter of common observation that all 

 vegetable life seeks the light or is attracted by it. 



