Meyer, Review of Publications of Bethe and Nissl. ' 41 



The sum total of the results of his studies of the cell-bodies in 

 poisoning and disease has convinced Nissl that the real core of 

 nervous function is only imperfectly touched by the histological 

 findings. Apathy and Bethe have established the view of M. 

 Schultze, that the fibrillary substance is the highest degree of 

 differentiation of cell-plasm of the animal body. It develops 

 to a great extent beyond the cell and persists outside of it. 

 * Ich schneide damit die hochwichtige und zur Zeit absolut un- 

 geloste Frage nach dem Wesen der grauen Substanzan.' Nerve 

 cells and their ramifications are not the essential criterionof the 

 gray matter. It is characterized wholly by the presence of 

 ' molecular ' substance in which the other elements are embed- 

 ded. Apathy claims that in the invertebrates the probably ho- 

 mologous neuropil is a continuous (anastomosing) net-work of 

 elementary fibrils. This condition is not established for the 

 vertebrates, but we have proof for the view that the functionally 

 highest parts of the nervous central organ contain large amounts 

 of this substance which cannot be glia and the existence of 

 which ' cannot possibly be simulated by the sum of nerve-cell pro- 

 cesses plus the non-nucleated glia in connection with non-medul- 

 lated and meduUated nerve fibers. ' , The proof of this consists in 

 the consideration that the dendrites in Bethe's specimens ramify 

 without division of the fibrils and that the number of fibrils in 

 the dendrites is so small after a few bifurcations that the ex- 

 tremely numerous ramifications of the dendrites in many Golgi 

 pictures is sheer impossibility. 'They cannot be the expression 

 of division of dendrites but must have another meaning.' At 

 least a part of the Golgi dendrites are supposed by Nissl to be 

 neurites which originate in the gray matter and go the nerve 

 cells to form the pericellular net of Held, demonstrable also in 

 Bethe specimens. Nissl goes so far as to say that the cells ex- 

 tend only as far as they are visible in the ' acute alteration ' in 

 Nissl specimens. 



Nissl finds himself forced to give up the neurone-theory 

 and to assume the following elements in the central nervous 

 system : 



" (i) nerve-cells and (2) a specifically nervous substance 



