DYNAMIC MONISM AND HEREDITY 
Nearly all writers on heredity in recent times have found it 
necessary to postulate some form of material vital units as gem- 
mules (Darwin), physiological units (Spencer), pangenes (De- 
V ries) , plasomes ( Wiesner) , biophores ( W eismann) . These biolog- 
ical units are necessarily regarded as different from the struc- 
tural units or molecules and composed of aggregates of them. 
A few authors have, indeed, seemed to identify the biological 
unit with molecules, but the way in which the concept was em- 
ployed shows that such identification was due to a confusion of 
ideas and not to any logical identification of the two elements. 
It is only necessary to indicate that the properties of molecules 
cannot rise above the nature of chemical reactions while the 
biological unit is postulated to explain an entirely different set 
of phenomena. All the attempts to cause these units to serve 
the purposes of heredity have served to illustrate the inherent 
weakness of the concept. Thus when the gemmules were required 
by Darwin to explain the fact that the germ in some way seems 
to represent the totality of the organism, he came to the absurd 
result that, if the gemmules were at least as large as molecules 
and every cell in an oak is represented in its germ, an acorn would 
need to be as large a bushel basket, not to mention the curious 
fact that every cell in every acorn would need to be represented 
in the germ of every other acorn. 
Various forms of corpuscular emanation theories avoid this 
absurdity only by falling into others. Even if a fundamental 
distinction is made between somatic and germinal elements and 
a continuity of germ-plasm alone is demanded to explain heredity, 
the problem is not rendered more intelligible, while it must be 
admitted that facts seem to prove conclusively the educability of 
the germ. The phenomena of everyday experience tend to 
show that the organism is a whole and that the germ up to a 
definite point in its history is as much a part of it as any other 
cell or organ. 
The solution offered for the problem of heredity by dynamic 
monism is as follows : The individual is a composition of cyclical 
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