8 
BIOLOGY: H. F. OSBORN 
sum of the forces inherent in environment, in individual development 
or ontogeny, in race development or heredity, and in natural selection. 
This conception was worked out more fully in 1912 and published in 
the form of a preliminary statement, as ''Tetraplasy, the Law of the 
Four Inseparable Factors of Evolution." During the past two years 
I have been engaged in workiiig out the aspects of this law from the 
standpoint of physics^ and chemistry, that is, interchange of energy, 
in preparation for the Hale Lectures before the National Academy of 
Sciences on ''The Origin and Evolution of Life upon the Earth." I 
perceive that it was an error to regard Selection as one of the four 
inseparable factors because it is not a form of energy. Consequently 
the law should be restated in the following terms : 
In each organism the phenomena of life represent the action, reaction, 
and interaction of four complexes of physico-chemical energy, namely, 
those of (i) the inorganic environment, {2) the developing individual {cyto- 
plasm and somatic chromatin), (J) the germinal or heredity chromatin, 
(4) the organic, environment. Upon the resultant actions, reactions, and 
interactions of each organism Selection is constantly operating whenever 
there is competition with corresponding actions, reactions, and interactions 
in other organisms. 
I believe this to be the most fundamental biologic law which can be 
expressed from our existing knowledge. It is in part an application to 
life phenomena, first, of Newton's third law of motion, ^ in the light of 
which physicists have given the full dynamical meaning to the modern 
laws of thermodynamics, second, of the laws of thermodynamics, and, 
third, of Darwin's law of Selection as developed J3y Weismann, Roux, 
Osborn, and others in modern biology. The reign of the laws of motion, 
including the motion of electricity, and of thermodynamics in the life 
processes follows as a necessary consequence of our modern physio- 
chemical interpretation of many of the phenomena which were formerly 
regarded as vitalistic. 
This law as operating between two or more organisms may be clearly 
expressed in the following scheme. 
Organism A 
Organisms B — X 
Physico-chemical Actions^ 
Reactions, and Interactions 
Natural Selection 
(Competition, 
Survival, 
Elimination, 
Physico-Chemical Actions, 
Reactions and Interactions 
of the 
Lifeless Environment 
of the 
Lifeless Environment 
