SPECIES IDENTITY OF NUCLEUS-PLASMA NORM 485 



it is necessary to consider depression from the point of view of 

 its metabolism. Activity itself could have been considered 

 from this point of view, since the actual basis for regarding 

 activity and depression as quantitative opposites is a metabolic 

 one. Incidentally, therefore, this discussion will be used to 

 round out the consideration of activity. 



The starting-point will be the resting cell, in the strictest 

 sense "sl cell in a state of preparedness for work, with any pre- 

 vious waste repaired." There is no external work but ''there 

 must be a constant display of internal work in maintaining its 

 structural integrity and carrying on its internal metabolism" 

 ('10). This is the recognized state of "tone." While the next 

 statement in this earlier discussion of nerve cell mechanics was 

 "it is assumed" that there is an exact balance, an equilibrium 

 between cell and nucleus, it is no longer an assumption, for the 

 constancy of the ratio of nucleus to cell both in the same and in 

 different animals of the species proves it beyond a doubt. The 

 assimilative and dissimilative processes of the cell must exactly 

 equal each other. More definitely, what the cytoplasm absorbs 

 of food material, what it gives to the nucleus, what the nucleus 

 returns to the cytoplasm, and finally what is consumed must 

 exactly equal each other. 



When now the resting cell is excited to the performance of 

 work, there is an obvious increase of all tangible materials and 

 the cell and nucleus enlarge to a size as much as 50 per cent 

 greater than that of the resting type from which they started. 

 Yet both plasma and nucleus increase in exactly the same pro- 

 portion, for the fixed norm of the nucleus-plasma relation has 

 invariably held for this first stage of activity. Both the intake 

 and the outgo are increased, likewise the interchange between 

 plasma and nucleus must be increased in both directions, yet the 

 same equilibrium is maintained quantitatively exact. This in 

 itself would seem sufficient to give an idea how function rests 

 upon a quantitative metabolic basis the same in kind but more 

 intense in degree than that of the resting cell. The actual 

 complete identity in substances involved could be shown if the 

 evidence were discussed that the whole metabolic process in both 



