12 PREFACE 



ply it. But to understand the actual inner operation of the 

 nervous mechanisms is a much more difficult matter, and this 

 knowledge cannot be acquired without arduous and sustained 

 study of the peculiar form relations of the nervous organs and 

 their complex interconnections; and information of this sort is 

 indispensable for a grasp of the principles of nervous organiza- 

 tion, and especially for an intelligent treatment of nervous dis- 

 eases. 



The study of neurology is, therefore, intrinsically difficult 

 if one is to advance beyond its most superficial phases; the more 

 so if the student is not well grounded in general biology and at 

 least the elements of the general anatomical structure of the ver- 

 tebrate body. To these inherent difficulties there is added a 

 purely artificial obstacle in the form of a cumbersome and con- 

 fused terminology which has grown up during several centuries of 

 anatomical study of the brain, in the early stages of which little 

 or no comprehension of the functional significance of the parts 

 discovered was possible, and fanciful or bizarre names were given 

 without reference to the mutual relationship of parts. 



The problems which at present chiefly occupy the attention of 

 neurologists are of two sorts first, to discover the regional 

 localization within the nervous system of the nerve-cells and 

 fibers which serve particular types of function or, briefly, archi- 

 tecture, and second, to discover the chemical or other changes 

 which take place during the process of nervous function, that is, 

 the metabolism of the nervous tissues. The first of these prob- 

 lems is at present further advanced than the second; the larger 

 part of this work is, therefore, devoted to a description of archi- 

 tectural relations. Without a knowledge of these relations, 

 moreover, the problems of metabolism are, in large measure, 

 meaningless. 



It is impossible to understand clearly the form of the brain, 

 and especially the relations of its internal structures, from verbal 

 descriptions merely. Pictorial illustrations and the various brain 

 models which are on the market are of great assistance; but ac- 

 tual laboratory experience in dissecting the brain and, if possi- 

 ble, the study of microscopic preparations of selected parts of 

 it are indispensable for a thorough mastery of the subject. 

 The brains of the sheep, dog, and cat are easily obtained, and 



