Nuclei Tuheris Laterales and the Ganglion Opticum Basale. 29 



supplied by three distinct types of nerve cells (p. 2), these three types 

 of nerve cells possess a fundamental similarity of cell character ; accord- 

 ingly the cell type varies as the cell function. In the second place I 

 have shown (Anat. Rec, 1913) that all cells supplying striated muscle, 

 whether directly (anterior horn cells, etc.) or more or less indirectly 

 (large pyramidal cells, cells of Deiters' nucleus, etc.) possess certain 

 fundamental features of cell character in common. This fundamental 

 character makes its appearance in the first cell of any efferent chain 

 which is set aside for the innervation of striated muscle and is present 

 in all cells of such a series, however many neurones may intervene 

 between the cell in question and the striated muscle fiber; on the other 

 hand the cells in such a voluntary motor chain differ in relation to their 

 position in the chain. It is thus evident that the particular group of 

 elements of cell type which corresponds to the motor function of the 

 cell may be distinguished from other elements of cell type which must 

 correspond to the other known or unknown influences. The feature 

 of cell character which corresponds to motor function is the arrangement 

 of Nissl substance in relatively coarse, discrete bodies; while the large 

 size (which is usually supposed to be common to motor cells) is not 

 directly related to the motor function, but is an element of cell character 

 which is probably (as stated previously) an indication of the extensive 

 connections of the cell, in that such a large cell receives impulses from 

 (sphere of reception) or sends impulses to (sphere of influence) a large 

 territory. 



Accordingly each type of nerve cell should be regarded not as distinct 

 from all other types, but as the result of different influences (due to 

 the various relations of the nerve cell to other neurones and to the other 

 portions of the organism) ; when so viewed the manifold variations of 

 cell type, including cells of the most diverse types, as well as those of 

 extremely similar types, do not appear to offer insuperable difficulties, 

 but on the contrary these confusing relations of cell types will enable 

 us eventually to work out the details of various nervous mechanisms. 

 After the simultaneous analysis, by the aid of many methods, of the 

 histological characteristics and the functional relations of difi'erent 

 types of cells, and after the recognition of the result of any given 

 functional relation upon the histological character of the cell, the neuro- 

 histologist will be able to take a further step. He will not only deter- 

 mine one portion of the functional relation through the presence of 

 certain features of cell character (which is already possible in the ease 



