THE RECOVERY FROM DEPRESSION 479 



the hyperchromatism of depression. It is a phenomenon then 

 of reorganization necessary for the restoration of the normal 

 nucleus-plasma balance. Howard ('08) verified Hertwig's find- 

 ings on the same animal under the same conditions, and contrib- 

 uted the further observation of pigment transformation within 

 the hypertrophied and hyperchromatic nuclei themselves. 



The parallelism with the nerve cell is definite in a common 

 state — depression, acting on a common source — nuclear materials, 

 with a common result — pigment. However, before going farther 

 the reader must, to avoid a misunderstanding, remember the 

 distinction between chromidia and chromidial apparatus: ex- 

 truded nuclear material of no functional value, against function- 

 ing extranuclear material, a specialized organelle of activeh^ 

 functioning cells. Chromidia as such have probablj^ no place 

 in the nerve cell. The resorption of nuclear materials by the 

 plasma is a normal process in that cell devoted to the upbuild- 

 ing of the chromidial apparatus, and hence even in profound de- 

 pression any interchange of nuclear materials follows that process. 

 The point of resemblance in this respect to the cells mentioned 

 is rather that in profound depression on account of the blocking 

 of interchange the material within the nucleus, while potentially 

 functional, is actually in a useless position, and in this restriction 

 it corresponds to the chromidia forming nucleus in possibilities. 

 Hence it is that pigmentation in the Purkinje cell is more essen- 

 tially an intranuclear phenomenon. However, the fate of cyto- 

 plasmic nuclear materials, though not chromidia in process, ap- 

 pears modified by the disorganized state of the plasma, and this 

 permits their transformation into pigment which will be discussed. 

 Further it may be that the change in tinctorial reaction leading 

 to pigmentation described around the nucleus is significant of the 

 plasmatic pigment being itself in part a resorption product. 



Further observations in the same category as the preceding 

 on the genesis of pigment from nuclear materials are as follows* 

 Rossle ('04) has traced, in the cells of melano-sarcoma, the ex- 

 trusion of nucleolar substance and its transformation into pig- 

 ment in the cytoplasm. Howard and Schultz ('11) have also noted 

 the occasional transformation of chromidia into pigment in 



