490 DAVID H. DOLLEY 



chromatin is comparatively small, as may be determined from the 

 resting cell which is normally without chromatin save in its karyo- 

 some. In accord with the earlier statement, however, the actual 

 increase of nucleolar substance "only makes more pronounced a 

 phenomenon which is sufficiently significant if that substance 

 maintains a level" and does not affect the interpretation. It is 

 extremely valuable in the evidence it offers that the nucleus has 

 direct metabolic relation with the external medium, as Verworn 

 originally stated ('91) and gives indication that the nucleus 

 synthesizes its own peculiar nucleolar substance from raw mate- 

 rials. In depression, the cytoplasm is primarily affected and the 

 nucleus relatively more spared throughout the process up to final 

 degeneration and so the nucleus continues to elaborate its own 

 nucleolar substance despite the plasmatic breakdown. Howard 

 and Schultz, in their studies on the biology of tumor cells ('11) 

 came to the same opinion of the constant production of nucleolar 

 substance and of its excess in depression: 



Whether, in this dependence of chromatin on nucleolar substance, 

 the necessary amounts of the latter are formed only in the nucleus 

 from materials derived from the cytoplasm, or whether nucleolar 

 substance can be preformed as such in the latter situation, cannot 

 be stated definitely. The constant production of nucleolar substance, 

 however, woilld seem to be a premise required for the explanation of 

 the continuous formation of chromatin and the ceaseless transferrence 

 of nuclear materials to the cytoplasm. That the production of nucleolar 

 substance may become excessive and exceed all the probable demands 

 of the cell we shall point out later in tumor cells. 



Finally, food remains to be discussed as a possible factor of 

 disturbance of the nucleus-plasma relation. The place of food 

 is in constituting the basis of the repair of waste and of the 

 maintenance of the balanced level of reserve capacity in the rest- 

 ing cell, and in supplying the elements for more active and 

 abundant synthesis in the functioning cell. The metabolic play 

 of function rests upon its food. It seems sufficiently established 

 that food alone is not competent to produce an overgrowth 

 (Adami '10). The overgrowth of either plasma or nucleus or 

 both that takes place in the various phases of the nerve cell's 

 activity is solely a functional overgrowth. A proper, even an 



