12 BIOLOGICAL PHYSICS 



It will be observed that the neural and neuronal 

 circulations are only indirectly continuous with the blood 

 circulation, inasmuch as they are separated from the blood 

 circulation by an intervening matrix of neuroglial sub- 

 stance in which the nerve cells are originally laid down, 

 from which they grow and interpenetrate the related 

 so-called non-nervous structures, and from which they 

 continue to maintain themselves and to exist as a great 

 nervous system, both materially and dynamically, circu- 

 lating alike and simultaneously the material and energy 

 necessary to nourish and innervate the neuro-musculo- 

 skeletal parts of the entire organism. 



The original disposition of the blastodermic layers lays 

 the embryonic foundation for the growth and differenti- 

 ation of the future systemic, or central, nervous system 

 and the growth of one system within another, with all that 

 is implied in such transcendental structural arrangements 

 of individual and united material and functional results 

 and high evolutionary developments. 



We are well aware that if these views be found tenable 

 an alteration of our foundation neurological doctrine will 

 become necessary, but, at the same time, hopeful that this 

 may be effected without, to any serious extent, involving 

 the disposition of the doctrinal substructure and super- 

 structure which have been so admirably reared on it ; 

 moreover, we are confident that the whole fabric must be 

 soundly constructed if it is meant to stand the increasing 

 strain of fresh accumulations of knowledge and yield the 

 practical results which it is entitled to afford to the pure 

 scientist, the physician, and the surgeon. 



The simplicity of working of the principle of circulation 

 throughout the entire confines of the body becomes more 

 and more obvious the further it is followed, until, becom- 

 ing dimly cognisant of its universality as an instrument in 

 development and evolution, we are compelled to give it a 

 place second to none in the economy of vital operations 

 and life. 



The continuity of its working and the union of its 

 various parts in the great chain of circulatory movements 

 give it an ideal place in the economy of development, 

 growth, and repair of organic structure, whether viewed 



