EXTRACT XXXV. 



ON NERVINE SECRETION AND EXCRETION. 



THE brain, cord, and ganglia may be compared with, and 

 described as, a Great Glandular Organ. It has been said 

 that "the brain secretes," that "it secretes thought and 

 nerve force," and in a functional sense this may be 

 regarded as true. In quite another sense, however, we 

 wish, for purposes of comparison, merely to describe 

 shortly how it may be compared with a glandular organ, 

 in order to make more clear and apprehensible some 

 of the heterodox views, which are so freely advanced by 

 us in these pages. 



That portion of the central systemic nervous structures 

 composed of brain, cord, and ganglia, has conveyed to, 

 and distributed without and within it, a very large blood 

 supply, the outer portion of the vasculature of which is 

 developed within the texture known as the pia mater, 

 while the inner, or proper, blood plasma distributing 

 vasculature is developed in the neuroglial matrix of 

 these central neuro-genetic masses. The former vascu- 

 lature, the outer, or true pia mater, with its extensions, 

 or inflections, known as the choroid plexuses, secretes 

 or exudes the fluid known by the name of the cerebro- 

 spinal lymph, the latter, or inner, exudes, or extravasates, 

 the substance known as the neuroglia, both parts of this 

 great circulation thus performing functions equivalent 

 to the blood circulations of organs known as true glands 

 the secretion of the outer pia mater being fluid, that of 

 the neuroglial vasculature viscous. Except in so-called 

 ductless glands, every secretion becomes an excretion, 



