ON THE NEURON 337 



or at anyrate wherever the elements of a systemic nervous 

 system are to be detected, whether scattered, or organised ; 

 therefore, the sympathetic, or trophic, neurons, having 

 primarily arranged themselves in definite groups, or gangli- 

 onic aggregations, assign to each of themselves, the super- 

 intendence of a definite area^ in virtue of which, the life, 

 growth, and functional activity, of that area, are sustained, 

 the health of the individual areas, necessarily, eventuating 

 in the health of the whole. The nervous systems of a 

 large portion of the lower animal world consist of, just, 

 such elements as are here described as we ascend higher, 

 however, in the scale of being, we see gradually taking 

 place, the addition of more highly organised parts, to these 

 almost automatic nervous systems, until, in the highest 

 ranges of animal life, a brain, spinal cord, and systemic 

 nerves, are introduced, in increasing completeness, and 

 complexity, when in the end we realise, in ultimate per- 

 fection, the union of the sy stems ^ in man himself, each with 

 its functional role respected, and its material development, 

 and evolution, fully matured. Further, we are of opinion, 

 that these two systems, the sympathetic, and systemic, can, 

 and do, act, both conjointly, and independently, and that 

 during sleep we see the sustained, and independent action, 

 of the sympathetic, or trophic nervature, as it is to be 

 observed in the earliest stages of embryonic existence, 

 and during paralysis of the cerebro-spinal system in any 

 particular part, or parts, of the body. We thus perceive, 

 that the structural integrity of the affected part, or parts, 

 is maintained by the same instrumentality, but, that while 

 the life, and structural integrity, of the part, or parts, in 

 question, are thus maintained, we become conscious, at 

 times, that changes of a retrograde, or degenerative, char- 

 acter, are in progress, and that the muscles are undergoing 

 processes of involution, in virtue of being cut off from the 

 sustaining, influence, and pabulum, supplied by the motor 

 nerves distributed to them ; also, that the skin, in like 

 manner, suffers, from the same deprivation on the part of 

 the sensory nerves distributed to it, becoming sleek, smooth, 

 and attenuated (Paget's " glossy skin ") sometimes to 

 the proportion of a mere pellicle, in which becomes visible 

 to the naked eye, as the sensory nervature atrophies, and 



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