preformation

[ pree-fawr-mey-shuhn ]

noun

1. previous formation.
2. Biology. (formerly) the theory that the individual, with all its parts, preexists in the germ cell and grows from microscopic to normal proportions during embryogenesis ( epigenesis ).

preformation

/ ˌpriːfɔːˈmeɪʃən /

noun

1. the act of forming in advance; previous formation
2. biology the theory, now discredited, that an individual develops by simple enlargement of a fully differentiated egg cell Compare epigenesis

Other Words From

• prefor·mation·ar·y adjective

Word History and Origins

Origin of preformation¹

First recorded in 1725–35; pre- + formation

Example Sentences

Let us first cast a historical glance at the older ontogeny, and the theory of preformation which is connected with it.

From Project Gutenberg

In any case, we can state today that the cytoplasm contains the rough preformation of the future embryo.

From Project Gutenberg

It is interesting to display the essential contrast between preformation and epigenesis in the poetical words of Wolff himself.

From Project Gutenberg

In this respect it is like its predecessor, the theory of preformation of the eighteenth century.

From Project Gutenberg

Preformation, identical with the original meaning of evolution, which see.

From Project Gutenberg