BIOLOGICAL PHYSICS 



The structure of the nervous system, as already 

 explained, is made up of a series of cells, and fibres, or 

 neurons (see Fig. 118), the axons of which latter, in 

 turn, are composed of a series of dual plastic rods, 

 one cylindrical, and hollow, and one solid, the latter 

 occupying the hollow in the former, encircled by their 

 respective tubules of neurokeratin ; the cells are laid 

 down in, and supported by, a matrix of neuroglia, in 

 which they are rooted by their dendritic (see Fig. 1 1 8) 

 processes, through which they extract their nourishment. 

 This may be regarded, as the primitive, and foundation, 

 structural condition of the systemic nervous system in all 

 its parts alike of the cerebrum, the cerebellum, the spinal 

 cord, and the ganglionic enlargements of the systemic 

 nerves, as well as the sympathetico-systemic system. 



The cells thus rooted, secrete and contrary to the 

 received teaching on the subject, we claim that, they also, 

 .do, and must, excrete indeed, it would be nothing short, 

 of " a contradiction in terms," and a physical impossibility, 

 that it could be otherwise. But, excrete what ? it may be 

 asked. We answer, that they, necessarily, must, and cannot 

 .do otherwise than, excrete, the substances known, as the 

 medullary, or " white substance of Schwann," and the axis 

 cylinder substance. They, thus, secrete, or provide, the 

 nutritive materials required for the maintenance of their 

 contained organisms, the nuclei, and nucleoli, the former 

 of which, the nuclei, in like manner, secrete from the cell 

 protoplasm, and excrete the substance of the axis cylinder, 

 while the nucleoli secrete from the nuclear protoplasm, 

 what they require, to enable them to continue their, 

 individual, and independent, existence, and active func- 

 tional role, and which must, of necessity, and in this case, 

 contrary to the rule, excrete, or shed, their effete materials 

 into the, as yet uncontaminated, or only self-contaminated, 

 nuclear contents, and axis -cylinder protoplasm these 

 so-called effete materials, it may be, becoming the intra- 

 axonal substance, or molecular strand, or channel, for the 

 conveyance, or passage, of nerve energy, into, or out of, 

 the cell. 



These excretionary substances, do not become fully, or 

 finally, excreted, or disposed of, until they have made a 



