ANIMAL AND VEGETABLE 



167 



not only by the nerve-sheath, but also by the sarco- 

 lemma. 



But if the nerve-fibre penetrates the sarcolemma, and 

 if nerve-substance and muscle-substance are in immediate 

 contact, then the transference of the excitement present in 

 the nerve to the muscle-substance is intelligible." 



The plexuses of the involuntary muscles probably form 

 part of a closed-circuit system designed to maintain 

 equilibrium. The plexus of Auerbach, as shown in 

 Halliburton, is, roughly, thus : 



Fig. 88. PLEXUS OF AUERBACH. 



(After Cadiat.) 



Without unduly taxing the imagination one could 

 conceive that plexus to be a distributing and equalising 

 station, provided in each of its branches and throughout 

 its ramifications with condensers of adjusted capacity, so 

 that at each and every point there would be, in normal 

 health, a certain given and definite tension. By " equalis- 

 ing " I mean an automatic " give-and-take " arrange- 

 ment to neutralise any excess or compensate for any 

 deficiency. 



