CRITICAL REVIEW OF THE DATA AND GENERAL 

 METHODS AND DEDUCTIONS OF MODERN NEU- 

 ROLOGY. 



By Dr. Adolf Meyer, 



Worcester Lunatic Hospital, Worcester, Mass. 

 Parti, With Plates XV to XIX. 



Neurological research seems to have struck a rich and im- 

 portant vein for progress in the shape of the ' neurone theory. ' 

 No less than a dozen pamphlets have during the last few years, 

 proclaimed this new fertile standpoint. The old division of 

 * elements of the nervous system ' into nerve-cells, nerve-fibers 

 and neuroglia is replaced by a simpler one — nerve-elements 

 (neurones) and neuroglia elements, A nerve-element, or neur- 

 one, consists of a cell body with nucleus and protoplasm and 

 processes, either of the character of the protoplasm — dendrite, 

 or of the character of a nerve- fiber — neurite. Nerve-fibers do 

 not exist by themselves ; a fiber is always a part of a cell only, 

 a process of a nerve-cell. Moreover, it is considered to be an 

 established fact that a fiber splits up into thin branches on its 

 course and that the ' collaterals ' and ' arborizations ' terminate 

 blindly without forming anastomoses with other cells. 



Like all progress of science, this new conception, called 

 neurone-theory, came to light in connection with a whole series 

 of new observations, in neurogenesis and neurohistology. We 

 shall see that it was slowly accepted in medicine, that it re- 

 ceived various definitions and that it is in reality almost as 

 if it meant simply the ' modern views of the nervous system.' 



Just now it seems as if a careful review of the fundamental 

 data and problems would hardly be out of place. Dogmatizing 

 without adequate basis has led to discrediting the 'neurone-the- 

 ory ;' certain facts seemed to militate seriously against its current 



