NEURAL AND H^MAL LYMPH 29 



organs and textures of the body are but engaged in 

 elaborating the distinctive varieties of a common fluid 



O 



for special or specific purposes. This common fluid may 

 be said to be typified by the liquor sanguinis, which 

 is the "finished article," resulting from the processes of 

 ingestion, digestion, sanguification, and regestion, and 

 the vehicle for the conveyance of all nourishment to all 

 structures, while all the other fluids found within the 

 body are but derivatives and specialised fluids, destined 

 for specific functional purposes, or for direct and indirect 

 elimination. 



The analysis of the cerebro-spinal fluid reveals a com- 

 position of considerable chemical complexity, as well as a 

 destitution of organised particles, and a preponderance of 

 what may be denominated preservative saline ingredients, 

 with a seemingly strange and apparently out of place 

 substance known as peptone. We emphasise "strange" 

 and "apparently," but have we not here a survival of 

 neurenteric function due to the existence of a common 

 embryonic origin, structure, and function, dating from a 

 period antecedent to the separation of the neurenteric canal 

 into its two divisions, and their subsequent almost, but 

 not complete, differentiation? The largely saline char- 

 acter, mainly from chloride of sodium, and composition of 

 the fluid seem to point to a necessary condition of asepsis 

 of the medium which is responsible for the hygienic irriga- 

 tion of the extra-, inter-, and intra-neural and peri-vascular 

 spaces of the brain and cord, and to the retention of a 

 chemical and molecular sweetness on the part of the some- 

 what faintly vital and amorphous material of the neuroglial 

 matrix ; moreover, we find, as already claimed, that a 

 medium is thus secured, in and through which nerve im- 

 pulse moves readily and spontaneously along the designed 

 molecular channels and nerve tracts, and that its continuity 

 and ubiquity are essential for the uninterrupted and full 

 working of the vast materio-dynamic machinery embraced 

 within the confines of the nervous system, central and 

 peripheral. 



The cerebro-spinal fluid, being constantly secreted or 

 exuded by the pia mater and associated choroid plexuses, is 

 distributed along the spaces and inter-spaces of the entire 



