PRELIMINARY NOTICE UPON THE CYTOLOGY OF 



THE BRAINS OF SOME AMPHIBIANS: 



I. NECTURUS.^ 



By Smith Ely Jelliffe, M.D. 



With Plates XII and XIII. 



In view of the great impulse which has been given to cyto- 

 logical work within recent years, the writer has felt that a study 

 of the cells of the brains of some of the lower animal forms 

 might give a clue to the correct interpretation of results ob- 

 tained with human material both normal and diseased. 



The study of the 'nerve cells by means of the methylene 

 blue stain (Nissl) has suggested a number of problems with far- 

 reaching results. The past few years have seen a large acces- 

 sion of workers using this method and the question, as the 

 writer sees it, resolves itself into one of interpretation. Is it 

 true that the physico-chemical changes taking place in nerve 

 cells are accompanied by constant changes in molar composi- 

 tion as Nissl claims ? Can these changes be registered and 

 studied by technical microscopical methods as outlined by 

 Hodge, Vas, Mann and numerous others ; and finally is the 

 Nissl method or its modifications such a method, and can its 

 pictures be relied upon to give accurate and trustworthy re- 

 sults ? Such a broad outline is, however, manifestly beyond the 

 purpose of the present paper which will simply state some 

 points of possible interest obtained thus far in a research 

 which the writer will hardly be able to complete for the 

 present. 



For a number of years it has been known that many cells 



1 The writer wishes to express here his thanks to Professors Osborn and 

 Wilson for their many courtesies and to Dr. Strong for his aid and advice while 

 working in the laboratory. 



