570 BIOLOGICAL PHYSICS 



assimilation by its various textures and organs, the fourth 

 method of circulation and nutrition comes into fuller 

 and fuller operation, until, to a great extent, it over- 

 shadows the first three ; but here, nevertheless, as between 

 the first three, the principle of union and co-operation 

 for common ends marks its advent into the combination 

 and the working of the future organism. 



The nutritive plasma is prepared and passed through an 

 alimentary tube by a highly organised series of circula- 

 tory structures, preparatory to its absorption into, and 

 vitalisation by, the haemo-genetic economy, after which 

 the various methods of nutrition are resorted to and the 

 wants of the whole organism are met by its passage into 

 cell, related cells, tissues, and organs by the methods 

 of circulation and nutrition, just described, under the 

 dynamic influence of innervation, intra-cellular, sym- 

 pathetic, and systemic. 



The various planes of nutritive activity, actuated by 

 these various methods of innervation, are represented by 

 the formative growth and organisation of certain struc- 

 tural bases ; thus, the uni-cell meets the necessity of 

 the first plane of nutritive work, the multi-cell community 

 the second, and the systematised arrangement of cell 

 communities the third, while the fourth has a huge matrix 

 of faintly organised material in the form of the entire 

 neuroglial substance from which to extract the elements 

 of its growth, development, and nutrition, as well as those 

 required for the growth, development, and nutrition of 

 skeletal muscle, and related, or histologically continuous, 

 textures, periosteal, osteal, and others. 



The plasma for the last, or systemic nervine, method of 

 nutrition, is deposited by the pia mater from its hasmal 

 vasculature amid the inter-spaces of the dense fibro- 

 cellular feltage of the neuroglial matrix, where it is 

 constantly available for purposes of neuronal nutrition 

 and neuronal protection as well ; each neuronal unit 

 supplying itself by its own absorptive economy from 

 the common neuroglial store, and passing its used-up 

 material on to its terminal distribution for final excretion 

 and disposal by its afferent, or efferent, end organs, as 

 the case may be. 



