THE LIVING SUBSTANCE. 67 



Protoplasmic Activities and Cell Division. 



By the word " activities " I must be understood to mean such 

 exhibitions of energy as directly or indirectly cause displace- 

 ment of the living substance, — as such, as area, as organ, or 

 as organism. 



Useful as it seemed to learn somewhat more of visible proto- 

 plasmic structure, there proved to be other facts whose impor- 

 tance transcended this. There is no doubt that in protoplasm, 

 as in artificial foams, there are structural differentiations which 

 imply certain physical stress and controls, resulting from the 

 mere physical conditions belonging to Butschli's foam structure. 

 This may readily be proven by observation and experiment. 

 But besides such phenomena, I find in the living substance 

 others which not only cannot be directly grouped with them, 

 but which even deny the possibility of such an explanation. 

 There exists here another set of controls constantly disturbing 

 and transcending, yet inseparably bound up with, arrangements 

 and equilibrations urged upon the substance by the given 

 physical foam nature, 



[74] In other words : The vital phenomena of protoplasm 

 were seen to be not so much manifestations of the visible 

 vesicular form of the substance, as upon, or through, this, 



(a) The most important phenomena of the living substance 

 are really to great measure independent of the visible foam 

 structure, I find them to be referable in all cases to activities 

 of the continuous substance of Butschli's structure, and to like 

 activities of the continuous substance of the finer foams, 



(b) In most cases they can be seen to pertain wholly to the 

 interalveolar stuff, and it is to this as organized, living, substance 

 that we must look for the clue to a bewildering labyrinth of 

 phenomena and possible interpretations, 



(c) In any visible foam structure, negation of such physical 

 controls as have been formulated for protoplasm, is always 

 expressed by the continuous substance, or is always to be 

 directly referred to it at any given moment. 



[75] Perfect as may be the structure of Butschli, or even a 

 finer foam, in any area ; stable as it may seem in any protoplas- 



