preformation


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pre·for·ma·tion the·o·ry

archaic theory that the embryo was fully formed in miniature within a gamete at the time of conception.
See also: homunculus. Compare: epigenesis.
Farlex Partner Medical Dictionary © Farlex 2012

preformation

(prē′fôr-mā′shən)
n.
1. The act of shaping or forming in advance; prior formation.
2. A theory popular in the 1700s that all parts of an organism exist completely formed in the germ cell and develop only by increasing in size.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

preformation

(prē-fawr-mā′shŭn)
In embryology, the development of structures from pre-existing templates, e.g., of bones from cartilage templates.
Medical Dictionary, © 2009 Farlex and Partners
References in periodicals archive ?
Returning to the "Transcendental Deduction," Kant finds that the analogy between rationalism and preformation, conceived of as a middle course between the empiricist view that experience makes the categories possible and his own position that the concepts of the understanding make experience possible, would involve a conception of the categories as innate subjective predispositions or habits of thought pre-programmed in us by our Creator, and agreeing exactly with the laws of nature, running alongside experience, that He created.
Likewise, because Godwin rejects preformation as a kind of institution, one might see perfectibility as closer to epigenesis, which describes the progressive development of an embryo out of the amorphous flux of an egg cell, or in Godwin's Lockean terms, the emergence of the mind from its originary state as "an unfinished sketch" through a process of division and self-differentiation (PJ 1798, 1:36).
Even worse, laments Pinto-Correia, modern writers on preformation have been guilty of wholesale fabrication.
Preformation of buds may be an evolutionary adaptation to a short growing season.
This assumption, coupled with religious commitments, led to the competing theories of preformation and epigenesis.
Otherwise, the partisans of the theory of preformation claim that every organism is completely predetermined in its germ.
His preformation theory of embryonic development survived in one form or the other until the 17th century.
Stone, Prebis, and others asserting that they mismanaged Thomas' medical condition and failed to diagnose abdominal abscesses, which resulted in preformation of his colon.
simple machine Time automatic machine Time 1 Thermal gluing of the 0,36 Thermal gluing of the 0,36 insertion in the sewing insertion in the sewing zone zone 2 Marking of the pocket 0,56 Positioning of the 0,18 position details 3 Application of the 2,4 Fixing the details and 0,35 insertion and preforming the pipe preformation of the pipe 4 Sewing the pocket 1,2 Sewing the pocket 0,40 5 Cutting the opening 1,3 Cutting the opening 0,18 Total 5,82 Total 1,47
The paradigm shift from the idea of preformation to that of epigenesis produced a new ambiguity: while all people are now equipped with the triumphal knowledge that they will pass on a biological inheritance, this triumph is undermined by the insight that each of us is the product of a biological inheritance.
This is a good reminder of how long ago the waxes were produced, when epigenesis had yet to fully overcome the idea of preformation.
Other regulatory genes (sections or provisions) include section 111 (captioned, "Operating Agreement; Effect on Limited Liability Company and Persons Becoming Members' Preformation Agreement") (172) and section 112 (captioned, "Operating Agreement; Effect on Third Parties and Relationship to Records Effective on Behalf of Limited Liability Company").