REVOLVING PLANTS. 53 



cell -wall and lodged in the general cavity, where 

 they continue to multiply in this geometrical ratio ; 

 and, joined by others similarly conditioned, now 

 develop the fine cilia and revolve within the original 

 revolving parental sphere. Not only so, but another 

 generation is generally commenced within these, 

 before the ever-expanding outer sphere bursts or is 

 gently opened. 



We have thus in each plant, globe within globe 

 revolving ; and when you get a number together 

 pure green and transparent each one revolving in 

 its own orbit and carrying similar revolving globes 

 within themselves, and the whole moving without 

 confusion or collision gracefully through the still, 

 clear water, you have almost a miniature of the solar 

 system under your gaze. If you have a vein for 

 poetry, the contemplation of the hidden beauty of 

 this little plant, thus revealed to your senses, is 

 enough to awaken it. But this is not all ; within 

 those globes are often seen veritable live animals 

 small rotifers, each one having a complex organisa- 

 tion. They are free-swimming creatures; and as 

 they move through the hollow sphere of the Yolvox 

 you can trace their mode of life, &c. I have often 



