Nuclei Tuberis Laterales and the Ganglion Opticum Basale. 31 



accordingly should with the aid of experimental work and of other 

 histological methods suifice to give much valuable knowledge as to the 

 real relations involved in any nervous mechanism. Every method of 

 studying the nervous system has its advantages, and I have employed 

 the Nissl method merely because of all methods it is the most valuable 

 in giving a complete picture of the cell groups of the entire nervous 

 system. To this peculiar advantage of this method, through which we 

 can compare the histological character of all cell groups of the nervous 

 system, I should like to direct especial attention. Such a complete 

 picture of the cell groups of the nervous system would seem to offer 

 a most favorable ground-work for assimilating to itself isolated facts 

 observed by means of all other methods of studying the nervous system ; 

 without other methods (histological, experimental, etc.) it is of course 

 of little value. (See last paragraph of introduction, p. 3.) 



In my opinion the demands of such work are so exacting that each in- 

 vestigator who attempts to gain a picture of the cell groups of a large 

 portion of the nervous system should confine himself, at least for the 

 most part, to one method, and of all methods that of Nissl shows the 

 cell structure in the clearest manner. It is not isolated cytological 

 details obtained by many methods, nor is it the proof or disproof of the 

 actual existence in the living cell of certain features of cell structure 

 that will be of most importance in the above outlined constructive 

 neuro-histology, but a thorough familiarity with the location, extent 

 and cell type of the different cell groups of practically the entire nervous 

 system, together with a most critical appreciation of the differences, 

 similarities and transitions of cell type of all these cell groups ; without 

 such broad knowledge of the various cell groups, which must of course 

 assimilate to itself isolated facts regarding the function and the connec- 

 tions of various cell groups directly and indirectly with one another, and 

 facts regarding tlie number, character, and mode of termination of the 

 cell processes of various cell types, without such a comprehensive knowl- 

 edge upon which to build we could not ho]w to penetrate far into the 

 exact relations of the individual neurones of the nervous system. 



LlTER.\TUl!E. 



The literature on the cell groups of the hypothalamus has been of 

 practically no assistance to me. In the first place I did not read it 

 until I had worked out these groups in the human brain, and upon 

 3 



