CHAPTER III. 



THE GENERAL CHARACTERS OF THE STRUCTURES 

 COMPOSING THE NERVOUS SYSTEM. 



BY MAX SCHULTZE. 



THE structural elements of the nervous system, speaking 

 generally, are of three kinds. To the conduction of nervous 

 influence the nerve fibres are subservient, which not only 

 compose the nerve trunks, but also constitute an essential part 

 of the substance of the central organs. At the peripheric 

 extremities of the majority of these fibres peculiar terminal 

 organs are found, representing the second structural element of 

 the nervous system ; whilst the third is formed by the peculiar 

 structures situated at the origin of each fibre in the nerve 

 centres. These are the ganglion cells. Our subject therefore is 

 naturally divided into a consideration of 



1. The nerve fibres. 



2. The peripheric terminal organs of the nerves. 



3. The centric organs of the nerve fibres. 



THE NERVE FIBRES. 



The nerve fibres form the chief constituents of all nerve 

 trunks, in which they are mingled with connective tissue and 

 blood-vessels ; they also enter largely into the composition of 

 the central organs, forming not only the whole of the white 

 substance, but constituting a considerable portion of the grey 

 matter. They are in part very simple, but in part also very 

 complex structures, and there are consequently several varieties 

 of them. The primitive nerve fibrils present the simplest 

 form. These are the very fine threads which lie on the extreme 

 verge of microscopic mensuration, and are only rendered visible 



