420 BIOLOGICAL PHYSICS 



messages for the central government are conveyed, and 

 from which all instructions and commands are passed out 

 from that central government, the machinery of this 

 government being carried about by its movable structural 

 surroundings, is ever available for the determination of its 

 direction and destination, save in the intervals of sleep, 

 when the interim direction and safe " keeping of the 

 house," are delegated to the never-ceasing services and 

 the ubiquitous watchfulness of the sympathetic "partner 

 in the business." The necessity for a common develop- 

 mental evolution and an unbroken histological continuity 

 of nervature and musculature thus become obvious, the 

 central nervous system developing its future receptive 

 and operative appendices by a continuous process of 

 growth, or addition, until it becomes conterminous with 

 the living and acting structures of the entire body, thus 

 innervating its entirety from periphery to centre, and from 

 centre to periphery, within the greater structural area of 

 the great sympathetic nervature. 



