EXTRACT V. 



THE SYSTEMIC NERVOUS SYSTEM, IN ITS RELATION 

 TO THE INCIDENCE OF DISEASE GENERALLY, AND 

 THE MANNER OF EVOLUTION OF ITS VARIOUS 

 DISEASES. 



THE systemic nervous system is, primarily, liable to attack 

 by a very large number of diseases, and, secondarily, to 

 affections invading or spreading to it from the so-called 

 non-nervous structures and fluids with which it is inter- 

 penetrated and surrounded. 



The primary affections may attack the cerebro-spinal 

 lymph, the neural envelopes or peripheral non-nervine 

 elements of that system, or they may, through and from 

 these, invade and involve the true nerve elements which 

 they contain, and in many cases these affections may 

 involve the whole structural elements, nervine and non- 

 nervine, of which the systemic nervous system is com- 

 posed, the juxtaposition and continuity of these elements 

 securing a universal involvement of the nervous system, 

 and, in certain cases, secondary implication of the inter- 

 penetrating and neighbouring non-nervine elements of 

 the affected organism. 



Each of the diseases included in the long list of purely 

 nervine diseases is characterised by an individuality, the 

 outcome of the nature of the mater if s morbi, the neural 

 element or elements attacked, and the sequence of the 

 morbid changes involved in the pathological process. 

 Thus, an attack of influenza may primarily involve the 

 cerebro-spinal lymph, the totality of which it may zymoti- 

 cally affect, and, everything being favourable, may pass 



