256 



THE LIFE OF THE PLANT 



scopic lumps of protoplasm, which are continually 

 changing their shape (fig. 73). Though on a smaller 

 scale they exhibit the same creeping movement as 

 that described in the case of plasmodia, a fact which is 

 easily understood, since plasmodia themselves, masses 

 of protoplasm visible to the naked eye, are formed by 

 the coalescence of a very great number of these micro- 

 scopic lumps derived from the spores (fig. 73). 



Thus we see that protoplasm, the foundation of every 



FIG. 73. 



cell, vegetable as well as animal, is endowed with a 

 peculiar movement, inadequately accounted for as yet, 

 and manifested indifferently whether surrounded by 

 a wall or entirely free as in the case of the plasmodia 

 of the slime fungi. 1 



These instances do not exhaust the phenomena of 

 movement, exhibited by the vegetable cell. So far we 

 have studied one kind of motion, the streaming move- 

 ment of shapeless masses ; let us now study the pro- 



1 There is a satisfactory attempt to explain this movement from the 

 physical point of view. Unfortunately we cannot dwell on it, because 

 it would take us too far into physics ; we can only say that by mixing 

 two liquids we can obtain, under the microscope, forms and movements 

 exactly similar to these. 



