Conceptions of Assimilation Reviewed 339 
in this descent the chemical energy which it enclosed 
within it in the potential state.” 
“Every act which gives out energy, which produces 
heat, or movement, every manifestation whatever, which 
can be regarded as a transformation of energy, neces- 
sarily consumes energy, and this is borrowed from the 
substances of the organism. The functioning muscle 
produces heat and movement, the functioning of glands 
produces heat, the functioning of nerve and brain pro- 
duces a small quantity of electricity and heat. All these 
manifestations of energy rest upon a destruction of 
organic matter, a chemical simplification as the source 
of the energy manifested. In this way material de- 
struction not only coincides with functional activity but 
is the measure and the expression of it.” 
“The reconstructive synthesis of protoplasm is on 
the contrary a phenomenon of evident synthesis, of a 
certain chemical increase of complexity. Its formation at 
the expense of simpler nutritive materials requires then 
an appreciable quantity of energy.” 
“The phenomena of living beings,” continues this 
author, “may be divided into two categories. Some are 
intermittent, alternative, and are produced or accentu- 
ated at certain times but cannot be continuous. These 
are functional processes. There are others in which 
this property of sudden and intermittent expenditure of 
energy does not appear at all. They are in general 
nutritive processes. The muscle which contracts, func- 
tions. It has an activity and a repose. During this ap- 
parent repose one could not say that it is dead. It has 
life and this is here obscure in comparison with the 
manifest activity of the functional movement.” 
“The phenomena of functional activity are those 
