It is interesting to display the essential contrast between preformation and epigenesis in the poetical words of Wolff himself.
This point established, two hypotheses remain: that of 'pre-existence' and that of 'epigenesis'.
The doctrine of epigenesis has very much complicated the whole question of heredity.
Digby's general theory thus represents a strange mixture of epigenesis and pangenesis, and is not entirely devoid of "virtues."
The development is an epigenesis, or impressing on identical material of different characters by different surrounding forces.
The differences between the exponents of evolution and epigenesis offer practical problems to be decided by experiment.
That then is our result: not evolutio, but epigenesis—epigenesis vitalistica.
Preformation: the doctrine of growth or development from already existing rudiments; opposed to epigenesis: q.v.
Elsewhere he writes: 'I believe that I have established that ontogeny can be explained only by evolution, and not by epigenesis.'
Wolff's epigenesis was not a complete explanation—indeed, from its fundamental conception it could not possibly be such.
epigenesis ep·i·gen·e·sis (ěp'ə-jěn'ĭ-sĭs)
The theory that an individual is developed by successive differentiation of an unstructured egg rather than by a simple enlarging of a preformed entity.