Lect. IX.] THE CURRENTS OF PROTOPLASM. 213 



a plant, wliicli we commonly regard as a merely passive 

 organism, is not easily forgotten l)y one who has 

 watched its display, continued hour after hour, without 

 pause or sign of weakening. The possible complexity 

 of many other organic forms, seemingly as simple as 

 the protoplasm of the nettle, dawns upon one ; and the 

 comparison of such a protoplasm to a body with an 

 internal circulation, which has been put forward by 

 an eminent physiologist, loses much of its startling 

 character. 



" Currents similar to those of the hairs of the nettle, 

 have been observed in a great multitude of very 

 different plants, and weighty authorities have suggested 

 that they probably occur, in more or less perfection, in 

 all young vegetable cells. If such be the case, the 

 w^onderful noonday silence of a tropical forest is, after 

 all, due only to the dulness of our hearing, and could 

 our ears catch the murmur of these tiny maelstroms, as 

 they whirl in the innumerable myriads of living cells 

 which constitute each tree, we should be stunned, as 

 with the roar of a great city."^ 



" I was curiously wrought," says the psalmist, — 

 wrought as with the fine needle of some skilful Eastern 

 maid, who makes " apples of gold in pictures of silver." 

 Any one who will watch the wonderful process of cell- 

 growth, and follow it through all its mysterious silent 

 j)assages and labyrinths, as seeing things that are in- 



^ Huxley, Od the Material Basis of Life. 



