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, then lies down again while 
the seeds are ripening, and raises itself a 
