100 STUDIES IN ELECTRO-PHYSIOLOGY: 



upon experiments with dead cells, and I have always 

 contended that the difference between the living and the 

 non-living is so great as to render results with the latter 

 not only almost nugatory but often misleading.' 



The valuable work of Dr. Mott, however, has thrown 

 new light upon the subject and helped to make clear that 

 which was previously obscure. He has found that the 

 basophile staining substance which forms the Nissl granules 

 does not exist as such in the living cells, but is the result 

 of coagulation. " If living cells are examined micro- 

 scopically with dark-ground illumination they are seen to 

 be filled with small granules or globules, each of which, 

 after escaping from the cell, remains discrete. 



Fig. 101. DRAWING OF AN" ANTERIOR HORN CELL, WITH PROCESSES. 



(After Mott.) 



" They are refractile," says Mott, " and appear white 

 and luminous ; this is due to a delicate covering film of a 

 lipoid substance which encloses a colloidal fluid, probably 

 consisting of a solution of salts and cell globulins. When 

 the cell dies this colloidal fluid is massed together in little 

 blocks the Nissl granules ; the intervening denser colloidal 

 substance is continuous with the colloidal substance of 

 the axon and dendrons. ... It thus appears possible that 

 these granules represent a large oxygen surface, like 

 spongy platinum, within the cell. When the cells die, the 

 lipoidal film of the globulin containing fluid is destroyed, 

 coagulation occurs, and the Nissl granules are formed. 

 These facts accord with the knowledge that stimulation of 



