THE AMERICAN NATURALIST. [Vol. XXXV 1 1. 



justifiable statements of the subject that has appeared. The neurone 

 theory is in essence the application of the cell theory to the complete 

 interpretation of nervous structures, in that the nerve fibres and the 

 neuropile are to be regarded as outgrowths and integral parts of ner- 

 vous cells whose bodies are represented by ganglion cells. Thus the 

 question of contact or continuity among neurones is set aside as 

 secondary and the real core of the matter is reached by the declara- 



Following the introductory chapter come eleven others devoted 

 each to the exposition and rigorous criticism of the views of some 

 well-known neurologist; among the investigators whose opinions are 

 here analyzed are Edinger, Hoche, von Lenhossek, Van Gehuchten, 

 Ramon y Cajal, Kolliker, Verworn, and His. The line of criticism 

 which pervades this part of the book consists in pointing out the 

 fallaciousness of the Golgi method and the failure on the part of the 

 neuronists to appreciate the full significance of the neuropile. The 

 Golgi method is notorious for incompleteness in its impregnations and 

 yet observations based upon it have been used again and again in 

 support of the idea that the neuropile is at least physiologically sep- 

 arable into discrete portions referable to given neurones. Since we 

 know so very little about the structure of the neuropile it would seem, 

 as Nissl rightly urges, that to pass it over simply as a terminal out- 

 growth of the neurone, or to ignore it almost entirely, as Verworn 

 does, is wholly unjustifiable. This treatment is all the more repre- 

 hensible because there is good reason to believe that the neuropile 

 may be the most important physiological element in the whole nerv- 



The concluding chapters, eight in number, serve to develop Nissl's 

 own views as to the structure of the nervous system. These are 

 based largely upon the work of Apathy and Bethe and centre chiefly 

 about the neuropile. The fibrillar network of the central gray, the 

 invasion of ganglion cells by the neurofibrillar, and the relation of 

 these to the pericellular Golgi network are discussed in much detail. 

 The scheme of nervous mechanism that Nissl constructs from 



