6 MICROSCOPIC PLANTS. [CHAP. 



Conferva one of the Oscillator ice. It is very simi- 

 lar in appearance to Zygnsema, but is much narrower, 



and the cells are very 

 short. Now look at them 

 under the microscope ; 



they are gently moving 

 over eac j 1 0^^ j n a ^ 



directions. It is from 



this peculiarity this oscillating motion they derive 

 their name. Mr. Berkeley says of this tribe of 

 plants : 



"Oscillatorice grow in various situations in salt 

 and fresh water, on damp ground, amongst grass on 

 close-shaved lawns, like lichens on the trunks of 

 trees, floating on the surface of lakes and seas, or 

 suspended like a cloud, giving rise to variously 

 coloured waters. One or two fine purple species 

 form thick woolly fleeces in the hotter parts of India, 

 while many inhabit hot springs." 



You think it strange that these low forms of plant 

 life should have the power of motion, but that is only 

 because you have been in the habit of observing large 

 trees and bushes which are fixed to the ground by 

 strong branched roots. Yet even these have certain 

 powers of movement at any rate, during portions of 

 their lives. Have you not observed how plants bend 

 towards the light, and how some that in the morning 

 inclined to the east, in the evening lean to the west ? 

 Then look at climbing plants, how they move round 

 a stick or string. Mr. Darwin, the great naturalist, 

 has written a book devoted entirely to the <! Move- 

 ments and Habits of Climbing Plants/' and probably 



