THE DYNAMICS OF CIRCULATION 189 



day in the organic time cycle, and must, therefore, be 

 reckoned, as of the same duration, as those immediately 

 before, and after. The rate of the circulation of the 

 structural elements, for the time being, therefore, of any 

 living structure, at any instant of time, must be deter- 

 mined by the rate of circulation of the atoms, or molecules, 

 composing them, and, consequently, by the consistence 

 and relative mobility of these, for the time being. 



Nutrition, being the central disposition of the tissue 

 plasma within the structural elements of the organism, 

 is effected by the resident organic forces operating under 

 physiological impulse, resident in, or emanating from, the 

 living tissues, and supplied from resident nervine sources, 

 and is, thus, a thing, not primarily effected by central 

 or systemic nervine influence, but by the sympathetic 

 nervature, it may be, of course, after drawing on the 

 resources of the central nervous system nutrition is, 

 therefore, an entirely sympathetic nerve operation, so far 

 as administration, so to speak, is concerned, and hence, 

 so far as we can see, it is not due to the existence of 

 any particular central systemic nerve mechanism, or trophic 

 nervature, or centre. 



The foregoing applies to the textures and viscera in- 

 nervated by the sympathetic nervous system, and, more 

 or less, to those dependent for innervation on a combina- 

 tion of the two nervatures ; while the nutrition of striped 

 muscle, wherever situated, must be regarded as entirely 

 effected by systemic nervine agency, through neuronal, 

 absorption, conversion, and utilisation, of neuroglial 

 plasma, or material, and axonal conveyance of it to the 

 muscle " end plates," and its final fibril distribution to the 

 sarcous, or muscle discs. The nutrition of the interstitial 

 muscle substance, being derived from, or effected by, the 

 blood (Fig. 67), under sympathetic nervine influence, 

 is not affected, except indirectly, by systemic nervine 

 conditions, hence the occurrence of such affections, as 

 pseudo-hypertrophic paralysis in which the one element 

 of muscle disappears, while the other remains, at least, 

 for a time the systemically innervated and nourished 

 representing the former, the sympathetically innervated, 

 the latter. 



