476 DAVID H. DOLLEY 



features, the problem relates to the less involvement of the 

 nucleus relative to the plasma in depression than in activity. 

 This nuclear relationship, even in advanced necrobiosis or in 

 permanent disorganization, brings about a condition quanti- 

 tatively analogous at least to that existing in the developmental 

 stage of the nerve cell. The cell emerges from the divisional 

 phase and enters on its function with a large nucleus but a 

 minimal plasma. Functional growth of both elements occurs, 

 but vastly greater in volume and content in the plasma. The 

 nucleus must preserve a similar influence in depression, and one 

 would predicate, therefore, the possibility of considerable plas- 

 matic functional growth with any existent nucleus, while such 

 a nucleus itself is also capable of further functional growth. 

 What its limits are from a minimal point must remain yet un- 

 determined. The consideration does, however, explain the 

 marked recovery after some time over the known effects of acute 

 profound depression and would lead one to expect still greater 

 recovery, say after years, if the depressant agent had ceased to 

 act. On the other hand, after some point of retrogression, par- 

 ticularly with a continuously acting depressant, perfect recoverj'- 

 becomes impossible just as in organic senility. 



Only such an irreparable damage can be declared a senility 

 of depression. The factors of permanence may be summed up 

 as follows, and at the same time compared with senility of activity. 



Senility of activity Senility of depression 



Structural end result 



Disappearance of cells. (Exhaustion.) Disappearance of cells. (Functional 



or disuse atrophy.) 

 Cell atrophy. (Nucleus relatively Cell atrophy. (Nucleus relatively 

 small to plasma.) ' large in volume and content.) 



Chromatic substance 



Nuclear chromatin: Absolute decrease Absolute diminishment in less degree: 



from normal; decrease relative to proportion to plasma greater. 



chromidial apparatus. 



Karyosome: Disappears earlier. Tends to persist very late. 



Chromidial apparatus (Nissl sub- Absolute decrease in greater degree: 



stance): Absolute decrease; propor- relative decrease to nuclear chro- 



tion to nuclear chromatin greater matin. 



than senile depression. 



No change tinctorial reaction. Definite change possible. 



