NERVOUS PLEXUSES. 291 



too analogous arrangements exist in some organ? 

 although perhaps not such striking ones. If we compare 

 the size of the nervous trunks in certain parts with the 

 total number of operations which are effected in an 

 organ, for example, in a gland, it can scarcely appear 

 doubtful that at least analogous arrangements exist there 

 also. This mode of distribution offers peculiar interest 

 in this respect, that many parts which are separated by 

 intervals of space are thereby connected with one an- 

 other. The electrical organ is composed of a number of 

 plates, but not every plate is supplied with nerves pro- 

 ceeding from the centre and intended only for it. The 

 silurus does not set one or other of its plates in motion 

 but is obliged to set the whole of them in motion ; it is 

 quite unable to divide the action. It can increase or 

 diminish the intensity, but must always call the whole 

 into operation. If in like manner we consider the ar- 

 rangements which prevail in certain muscles, we find 

 there is no evidence to justify us in assuming that every 

 portion of a muscle receives special, independent nerve- 

 fibres. On the contrary, a special division of nervous 

 action in muscles only exists to a very limited extent, as 

 we know from our experience in our own bodies. The 

 neuro-pathological doctrines would lead us to infer that 

 the will, or the soul, or the brain is able by means of spe- 

 cial fibres to act upon every single part, but in reality 

 this is by no means the case, for the nervous centres 

 have mostly only one single path by which they can 

 communicate with a certain number of similar elemest- 

 ary apparatuses. 



Now with regard to nervous pkxuses, we are at the pre- 

 sent time acquainted with most extensive arrangements 

 of the kind in man, in the submucous tissue of the intes- 

 tines, where the relations have recently been more closely 

 investigated, in the first instance by Meissner and after- 



