Meyer, Data of Modern Neurology. 135 



tral ganglion for each inner segment and longitudinal connecting 

 strands between the ganglia. The structure of these ganglia is 

 illustrated by the following elements : 



Specialized ' sensory ' cells among the epithelia of the skin 

 send fiber processes into the ganglion where they dissolve in an 

 arborization, coming into contact with the branches of the cells 

 which are connected by a process with the muscles located 

 under the epidermis ; and further cells, the processes of which 

 merely connect various parts of one ganglion or of several gang- 

 lia together. 



This gives us the following three types of elements : 



1. Afferent elements, specialized epithelia, which send a 

 fiber process into a ganglion where it ramifies into branches 

 ending in contact with many cells ; one or more of the 

 branches may even join the longitudinal strand and terminate 

 near the cells of neighboring ganglion. The fundamental point 

 is that one spot in the sensory surface (skin) becomes con- 

 nected with many cells. ^ 



2. Shunt cells or intermediate elements, cells which mere- 

 ly connect various parts of one or more ganglia. Their pro- 

 cesses do not leave the 'central nervous system.' 



3. The motor nerve-elements, called 'motor' because they 

 are in definite connection with the muscles. The cell body 

 forms part of the ganglion, its fiber a part of the ' peripheral 

 nerve', and the termination corresponds to the muscular end- 

 plate. 



iThe afferent elements are usually called sensory ; this term is however 

 greatly misleading. If sensory is to mean 'the bearer of sensation,' it is wrong ; 

 for the sensation lies not in these elements, but in a mechanism or combination 

 of many cells. If the cord is severed in a vertebrate, the afferent fibers 'below' 

 the lesion remain afferent, as the presence of reflexes shows; but they are in no 

 manner sensory, bearers of sensation. It is the custom of carrying incompletely 

 digested or obsolete psychological terms into physiology which leads us to this 

 laxity of terminology. In the future study we shall rather avoid the word sen- 

 sory as an anatomical attribute and reserve it to psychophysical processes except 

 perhaps where stilistic reasons seem to demand leniency in the choice of 

 synonyms. The term 'afferent' is as a rule more correct and preferable, because 

 it says just what is meant and suggests no false psychical inferences. 



