120 Phenomena Refuting Simple Epigenesis 
follows therefore that each fact or each argument which 
speaks in favor of nuclear somatization, is at the same 
time a proof against epigenesis. And we saw precisely 
in the preceding chapter, that there is a whole series of 
facts and arguments, which it would be useless to repeat 
here, but which compel us to admit this nuclear 
somatization as an incontrovertible fact. 
The preformationists can finally object to epigenesis 
and not unreasonably, that by its “attainment of equilib- 
rium,” it does not explain the termination of ontogeny 
as well as preformation does. For why should the 
reciprocal actions of all parts, on which development 
depended up to that time, suddenly cease to effect any 
further change when once the adult stage is reached? 
Because it is only then, reply the epigenesists, that the 
dynamic equilibrium is attained. But if the successive 
ontogenetic forms repeat the phylogenetic, how comes 
it that the dynamic equilibrium which once existed in 
each of these latter does not remain existent in any of 
the former? And if the absence of equilibrium at all 
these stages is due to some alteration of the formative 
living substance, how then could this new substance pass 
again during a long series of stages through the same 
phylogenetic ancestral forms? The preformists, on the 
contrary, have no trouble in explaining the arrest of 
development since according to their theory it would 
follow only at the moment when there would be present 
in each cell only a single kind of preformistic or 
determinant germs. 
Having thus made a rapid review of the principal 
objections which compel us to reject epigenesis, we can 
pass on to an equally brief consideration of a number 
