614 Causes and Course of Organic Evolution 



ory of primitive kind. A rhythmic energy distribution con- 

 nected with one of several stimulatory acts becomes so adjusted 

 to the molecular mechanism as to start and to effect movement, 

 even in absence of the stimulus. The plant, in other words, 

 has formed a habit. 



But as already traced out in Chapter IX (p. 226) we would 

 consider that early separation of a cogitic or neuratin constitu- 

 ent of the cell took place amongst the higher Protozoa. By 

 steady increase in amount and complexity, this gave rise to the 

 evolving nervous system of invertebrates and still later of ver- 

 tebrates, till it reached a climax of amount and complexity in 

 man. During this process myriads of proenvironal acts were 

 performed in the history of each evolving individual and species. 

 All such resulted in a temporarily satisfied state, that either 

 conduced to advance, or stagnation, or even degeneration of 

 the organism. But the combined states, in relation to definite 

 environments, that proved most beneficial to some animal 

 organisms, became by oft-repeated acts instinctive tendencies of 

 a hereditary kind, through establishment of definite stereoenerg- 

 izing currents along definite molecular pathways of stimulation. 



These probably mainly altered the protoplasmic and nuclear 

 or bio-cognitic material at first, but, gradually affecting and 

 altering neuratin constituents of the nerve cells, produced in 

 these such stereochemical placing of its highly complex Nissl or 

 neuratin molecules that repetition of an act would tend to be 

 started, even when an incomplete or partial stimulation act 

 only affected the neuratin substance. 



So we would associate manifold stored nervous impressions 

 or compounded resultant sensory states with the neuratin sub- 

 stance of nerve cells, while the stereoenergetic tendencies that 

 have become associated with the stereochemical molecules of 

 these cells together constitute what in the past have been called 

 instincts. But increase in the number, variety, and rapid cor- 

 relation with each other of these instincts has gradually estab- 

 lished that exhibition of animal activity that is known as intel- 

 ligence. For this is the view that is more and more being ac- 

 cepted by physiologists and psychologists. 



