Gemmule (pangenesis)

Gemmules were imagined particles of inheritance proposed by Charles Darwin as part of his Pangenesis theory. This appeared in his book The Variation of Animals and Plants under Domestication, published in 1868, nine years after the publication of his book On the Origin of Species.

Gemmules, also called plastitudes or pangenes, were assumed to be shed by the organs of the body and carried in the bloodstream to the reproductive organs where they accumulated in the germ cells or gametes. They thus provided a possible mechanism for the inheritance of acquired characteristics, as proposed by Jean-Baptiste Lamarck, which Darwin believed to be a cause of the observed variation in living organisms.

This was prior to the 1900 rediscovery among biologists of Gregor Mendel's theory of the particulate nature of inheritance.

(from The Variation of Plants and Animals under Domestication (1868), Charles Darwin)

It is universally admitted that the cells or units of the body increase by self-division, or proliferation, retaining the same nature, and that they ultimately become converted into the various tissues and substances of the body. But besides this means of increase I assume that the units throw off minute granules which are dispersed throughout the whole system; that these, when supplied with proper nutriment, multiply by self-division, and are ultimately developed into units like those from which they were originally derived. These granules may be called gemmules. They are collected from all parts of the system to constitute the sexual elements, and their development in the next generation forms the new being; but they are likewise capable of transmission in a dormant state to future generations and may then be developed.)

(from Charles Darwin: The Power of Place by E. Janet Browne):

Individual gemmules did not contain a complete microscopic blueprint for an entire creature in the way that Herbert Spencer or Carl von Nägeli described.' (p.276)

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