160 THE BEAUTIES OF NATURE chap. 



of bodies called spores, which an untrained 

 observer would certainly suppose to be animals. 

 They are covered by vibratile hairs or " cilia," 

 by means of which they swim about freely in 

 the water, and even possess a red spot which, 

 as being especially sensitive to light, may be 

 regarded as an elementary eye, and with the 

 aid of which they select some suitable spot, to 

 which they ultimately attach themselves. 



It was long considered as almost a charac- 

 teristic of plants that they possessed no power 

 of movement. This is now known to be an 

 error. In fact, as Darwin has shown, every 

 growing part of a plant is in continual and 

 even constant rotation. The stems of climb- 

 ing plants make great sweeps, and in other 

 cases, when the motion is not so apparent, it 

 nevertheless really exists. I have already 

 mentioned that many plants change the posi- 

 tion of their leaves or flowers, or, as it is 

 called, sleep at night. 



The common Dandelion raises its head 

 when the florets open, opens and. shuts morn- 

 ing and evening, theii lies down again while 

 the seeds are ripening, and raises itself a 



