On Inheritance in Evolm 
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So long as nutrition of the germ-cells continues, the building of 
structure in which they become the chief agents must be for this 
reason also subject to the influences which are experienced by all 
the other cells of the body, under the strains and other stimuli 
derived from the interaction of the individual and its environment. 
The relation of inherited and acquired characters in a series of 
generations may be graphically represented as follows : Let 5 
represent the aggregate of character of the body {soma) of a given 
species in process of progressive evolution or acceleration. Let 
g represent the aggregate of characters potential (or dynamically 
present) in the germ cells of the same individual. For the sake 
of simplification of the problem I consider here only one sex, 
and imagine the reproduction to be parthenogenetic. Let A rep- 
resent the new character acquired by the soma under the appro- 
priate stimulus, and let a represent the same characteristic as it is 
impressed on the germ plasma of the same individual at the same 
time, and in consequence of the same stimulus. The history' of 
the acquisition and incorporation of newly acquired characters 
by the line of descent originating with the species S+g, may be 
