EXTRACT XXXIV. B. 



ON THE COMBINATION OF SYMPATHETIC AND 

 SYSTEMIC MUSCULAR INNERVATION. 



THAT the sympathetic nervous system is possessed besides 

 a musculature of what is equivalent to one, i.e. a con- 

 tractile mechanism, whereby it can effect the shortening 

 and lengthening, or regulation, of certain organic textures, 

 is a belief which, more and more, grows in strength upon 

 us as we succeed in differentiating it in structure and 

 function from the proper musculo-nervous system. Thus, 

 the contractile mechanism, by which the shrinkage or con- 

 traction and relaxation of the perineo-scrotal textures is 

 effected, seems to be repeated, wherever the phenomena 

 of rapid cutaneous shortening and lengthening have to be 

 accomplished, as for instance in the orbits, without the 

 presence or aid of muscular fibre, and where necessarily a 

 pseudo-muscular fibre is innervated by the sympathetic 

 nervature ; and that this belief is well founded we are now 

 fully convinced, and we would observe that such contractile 

 movements are apparent when the systemic nervous system 

 is entirely detached and insulated from the sympathetic 

 nervous system, as in sleep and in some forms of paralysis, 

 when vaso-motor phenomena generally, and cutaneous 

 transpiration and perspiration phenomena are determined 

 and regulated necessarily by the sympathetic nervature, 

 through the contractile agencies resident in the structures 

 concerned ; but whether the principle of a dual control 

 could be admitted here it is premature to say, further than 

 that it is highly probable. The cutaneous musculature, 

 apart from such sub-cutaneous muscular developments 



