vi authoe's preface to': the fifth gehman edition. 



mostly by physicians. To them, naturally, the first task was to gain a 

 better understanding of the hiaman brain, only the mammalian brain being 

 brought in for comparison. We possess, however, even of the lower verte- 

 brate types, several excellent descriptions. 



By comparing animals low down in the vertebrate series the attempt 

 is here made to determine where particular structiires appear, how they vary, 

 and what functions they may perform at different stages of their develop- 

 ment. It has also been attempted to determine what belongs to each 

 separate part of the nervous system as essential and fundamental. It is an 

 attempt in which the author believed himself justified, in view of the fact 

 that he had been occupied ten years in studies in the realm of comparative 

 neurology. 



The preface to the second edition of this book closed with the following 

 words: "There must be a number of anatomical mechanisms which are alike 

 present in all vertebrates: those which malce possible the simplest expres- 

 sions of the activity of the central nervous system. It is only necessary to 

 find that animal, or that stage of development of any animal, in which this 

 or that mechanism appears in so simple a form that it may be completely 

 understood. Once one has anywhere perfectly established the relation of 

 such a mechanism — e.g., a nerve-bundle or a cellular structure — he is usually 

 able to readily find it again even where, through adventitious matter, it is 

 made more or less obscure. The discovery of such fundamental features of 

 brain-structure appears to be the next and most important task of brain- 

 morphology. Once we know them, it will be easier to understand the com- 

 plicated mechanisms with which the more highly organized brain performs 

 its function.'"' 



This was, in a way, a programme which has, in part, been carried out in 

 the new edition. 



Edingek. 



FBAXKiriiT-AM-;\lAIX, JUXE, 



