Note 7 — Chapter V

The evolutionary development of this instinct is not altogether mysterious. Science can fairly well trace the successive steps in the development of the central nervous mechanism, from the amœba to the highest type of vertebrate. "Nerve channels" are worn by the repeated transmission of impulses over the same tracts. Coördinations become in successive generations more complex and more perfect. As consciousness develops further, in each succeeding type, actions originally reflex tend to take on a more consciously purposeful character. But all we are concerned with now is the problem of tone-production. Our purpose is best served by accepting the faculty of muscular adaptation as an instinct, pure and simple.