110 PROTOPLASMIC NERVE THEORY. 



These, indeed, have been the chief stumbling-blocks in 

 the way of the acceptance of the protoplasmic theory, 

 and, singularly enough, even to those persons who 

 show the most inclination to reduce all vital pheno- 

 mena to mere chemical and physical actions. 



As the function of the muscles is intimately con- 

 nected with that of the nerves, it will be more con- 

 venient to begin with the general question of the 

 structure and functions of the latter, although the full 

 discussion of the theory of the nerve-action cannot be 

 completed till we come to the muscles. The anatomi- 

 cal element of the question is of primary importance, 

 for the differences between Dr. Beale and other ana- 

 tomists on several essential points are irreconcilable, 

 and if he be right many prevailing theories will have 

 to be very much modified or abandoned altogether. I 

 may, therefore, give an analysis of the chief features of 

 his anatomy of the nervous system and the physio- 

 logical deductions founded upon it. 



The development of the nerves always proceeds pari passu 

 with that of the tissue to which they belong : new nerve fibres 

 are never developed so as to influence old muscular fibres, nor 

 old nerve fibres caused to influence newly-developed muscular 

 tissue, but if wasting takes place the whole are removed 

 together, and if regeneration takes place the new tissue is 

 formed from formless spherical masses of germinal matter 

 complete ("Croonian Lecture," 1805 264). The protoplasm 

 or bioplasm in many of the textures performs no other office 

 than the formation of them ; but, " in every part of the ner- 

 vous system, however, more especially at the peripheral distri- 

 bution and central origin of all nerves, active changes of the 

 most important kind are effected through the agency of the 

 bioplasm, and these continue throughout life. Indeed, in 

 some instances, nerve action, which is dependent upon changes 



