360 BIOLOGICAL PHYSICS 



principle, or vital force, approach, merge, and continue 

 the living characteristics of the parental sources from 

 which they were shed, transmitting, from one generation, 

 to another, in succession, the original life principle, to be 

 clothed in organic form, according to environment, and 

 preceding condition of life "like producing like," and 

 like, plus modification, producing like, plus modification, 

 in endless succession, and increasing variety. 



The sympathetic nervous system, so-called, therefore, 

 becomes synonymous with every non-systemically inner- 

 vated living structure, and is possessed of the dynamic 

 powers of life, or the vital qualities, constituting that 

 inscrutable entity, in its relationship to organic matter, and 

 the succession of life forms. By it, every organic atom, 

 or molecule, is brought into vital line, and continuity, in 

 the formation of every living cell, or in the building up of 

 every structure, and organ, of every living creature, for 

 the preservation in health of that creature, with its specific 

 characteristics, material, and dynamic, in order to maintain 

 the great " sequence of events," involved in the great 

 process of evolution. 



These views necessitate a belief, in the parallelism, and 

 convertibility, of the terms, sympathetic nervous system, 

 and all varieties of cell, and fibre, structure, embraced 

 within the economy of an organic body, other than those 

 innervated by the systemic nervous system. From this, 

 the further belief is necessarily deducible, that all living 

 organic elements, or structures, are divisible into two 

 categories, according to their manner of innervation, and 

 that the many forms of structure known to anatomists, 

 and histologists, are but names for the various modifica- 

 tions of nervine development, as they become evolved by 

 increasing functional complexity, due to variation of en- 

 vironment, and continued elaboration of structure, and 

 function, to meet increasing organic wants, and dynamic 

 requirements. 



Such a division of the textural elements of the most 

 complicated living organism, simplifies the conception of 

 its working, shows more clearly, and intelligibly, the inter- 

 dependence, and co-ordination, of its various parts, and 

 organs, and brings into relief the continuous " adaptation 



