ON NUTRITIONAL CIRCULATION 45 



circulative stages being merely vehicular, and subservient 

 to the great function of nutrition, with its implied meta- 

 bolism. The processes or phenomena of nutrition being 

 universally dependent on the economy of circulation, we 

 perceive that the necessity for the existence of trophic 

 .centres within the systemic nervous system is lessened or 

 negatived, and, at the most, is based on the regulation of 

 the vaso-motor neuro-muscular agencies by the sympa- 

 thetic nervature, a system of nutritive, or trophic, inner- 

 vation, which is all-powerful, and sufficient in all living 

 organisms not possessed of a systemic nervous system, 

 with the exception of muscular structures and the textural 

 elements of the skin, which are dependent for their 

 nutritive pabulum on the systemic motor and sensory 

 nervatures respectively. 



Broadly, it may be stated that the meso- and hypo- 

 dermal structural elements are dependent for nutritional 

 pabulum on circulatory media innervated by the sympa- 

 thetic nervature, and that the endodermal structural 

 elements are dependent for nutritional pabulum on the 

 circulatory media resident in the central or systemic 

 nervous system, which, in addition to the possession of 

 its own nervine energy, is structurally and vitally inner- 

 vated by the underlying and inter-penetrating sympathetic 

 nervature. The sympathetic nervature thus continues to 

 be the great, if not the sole trophic nervature, leaving the 

 systemic nervature to innervate and control those parts of 

 the organism to which it is histologically distributed, and 

 whose nervature is purely systemic, or only secondarily 

 responsive to sympathetic influence or stimulation. 



The media responsible for the circulation of nutritive 

 materials thus also become the media for the circulation of 

 *vital energy, more especially in the cryptic structural 

 regions in which the phenomena of metabolism take place, 

 and where the nutritive processes are wrought out amid 

 the molecular interstices of the more or less homogeneous 

 tissues. Metabolism and nutritive circulation in their 

 terminal stages may, therefore, be regarded as processes 

 of physiologico-chemical circulation where the circulation 

 is reduced in dimensions to the proportions of an atomic 

 procession into and out of the vitally coherent mass of 



