4(54 DAVID H. DOLLEY 



5" in all publications). This applies to young dogs from ten days 

 to five weeks, becoming progressively less marked. 1 was fooled 

 by it until the incongruity of the measurements showed there 

 was something wrong. The cytoplasmic edema is the clue in 

 such cases. Edema is absent in the resting cell, but present in 

 the confusing one. 



Since so much is to be said about the factor of senility, its 

 resting type demands a word. In frank old age without actual 

 loss of cell organelles there is an appreciable deficiency of every- 

 thing, of chromatin and nucleolar substance in particular, though 

 the features of the virile cell are in the main preserved. There 

 is a resultant shrinkage and irregularity of the cell and nucleus 

 whose degree depends on the degree of senility. The difficulty 

 in old age comes in difTerentiation from that same stage of activity 

 as in early youth. This is due to the fact that the resting nucleus 

 of age may be so deficient that it has the reticulated structure of 

 the above transition. Here also in a declining hyperchromatism 

 the cell comes to a semblance of the normal resting extra-nuclear 

 content. Further, the resting cell is irregular from age and 

 smaller than in youth, while the confused cell is also irregular, 

 though usually more so, and small, that being its nature as a 

 Hodge stage. Even with experience the diagnosis is frequently 

 impossible, though it is not a practical matter as other cells less 

 changed are at one's disposal. 



This is the cell, so characteristically individual, that is regarded 

 as one in functional rest, though in 'tone' and prepared for 

 work. Earlier measurements confirmed its place. Additional 

 data predicate that in one phase of its size relations there is the 

 constancy of a law. Holding to that law as sufficiently estab- 

 lished, one may add to the objective definitive points enumerated 

 for the resting cell of the dog species the measured property of 

 a nucleus-plasma coefficient constant for the species. It is true 

 that at one transition point of activity an identical figure is 

 reached and will be reached in every nerve cell above a certain 

 point of differentiation. This is in passing from the maximum 

 of upset in favor of the nucleus (earlier nuclear hypertrophy) 

 to the final reversal in favor of the cytoplasm (ensuing cytoplas- 



