system are three; nerve fibres, which are simply conducting threads,
telegraph wires; ganglion cells, which are the officials of the system;
and neuroglia, a fine variety of connective tissue which holds these
other elements together, and may also possibly exercise a function in
affecting impressions. A message along a nerve to a ganglion cell is
an afferent impression, from a cell to a muscle or other external end
is an efferent impression. The passage of an impression may be
defined as a flash of kataboly along the nerve, and so every feeling,
thought, and determination involves the formation of a certain
quantity of katastases, and the necessity for air and nutrition.