244 Papers from the Department of Marine Biology. 



in it, but the plasmosome is always found on the kathodal surface 

 of the perichromatin mass, and while it never touches nor sticks out of 

 the surface, it does appear to press up in a way that makes a little 

 mound of the perichromatin above it. Neither the plasmosome nor 

 the kaiyosornes are changed in structure or size by treatment with 

 currents of this strength. 



The kathodal end of the nucleus contains a very fine reticulum of 

 meshes, the fibrils of which pass largely in the line of the electric 

 current. Sometimes, or even usually, these meshes appear to hold 

 one of thekaryosomes, which has therefore not been able to move toward 

 the anode and join its fellows that are distributed very generally 

 through the modified perichromatin mass. Two such cases are to be 

 seen in one cell and one in the other cell pictured in figure 19, plate 4. 



This kathodal reticulum grows denser toward the kathodal surface 

 of the nucleus and appears to have in it very fine granules of a chromatic 

 material, chromatic at least with regard to iron hematoxylin, but not 

 quite so strongly to the carmines. 



It will be interesting to draw a short comparison between the 

 action of the electric current on this large, highly differentiated nucleus 

 of the electric motor nerve-cell and the small nuclei of some of the 

 surrounding connective- tissue cells. Such nuclei are seen in figure 19, 

 plate 4, and in them one sees a rude approximation to the conditions 

 seen in the nerve-cell. The chromatin has been moved toward the 

 anode, but has not been melted or dissolved into a homogeneous median 

 as in the electric nerve-cell. The chromatin masses are still more or 

 less distinct and no large plasmosome is apparent. This comparison 

 may serve as an index of the superior analytical conditions to be secured 

 by experimenting electrically with a large, highly differentiated cell 

 (such as this nerve-cell) rather than with smaller tissue-cells such as 

 have usually been worked with. 



As for the exact processes by which the nucleus of the electric motor 

 nerve-cell has been so changed, there is room for difference of opinion. 

 It is certain that a large part of it is purely physical and mechanical, as 

 described by many writers, but in the present case there appear to have 

 been chemical changes as well. The perichromatin seems certainly 

 to have undergone some melting or solution of its finer particles (the 

 perichromosomes) and a mixture of this with the nuclear fluid ; also the 

 reticulum in the kathodal half of the nucleus seems to be an entirely 

 new structure chemically. Further, the chromatic material in this 

 reticulum, as well as the deep-staining material in the kathodal sector 

 of the cytoplasm, appear to be materials that do not differentiate from 

 the rest of the cell under any other circumstances. 



The main point, however, that we learn from this experiment, a 

 result that is obtained by all repetitions, is that the plasmosome is not 

 moved by this strong electric current all the way toward the kathode, 



