gemmules

Noun

gemmule (plural gemmules)

1. (archaic) Synonym of gemma (“an asexual reproductive structure, as found in animals such as hydra (genus Hydra) and plants such as liverworts (division Marchantiophyta), consisting of a cluster of cells from which a new individual can develop”)
   • A very similar mode of growth and propagation is found among the compound Polypes, whose gemmules, like those of the Medusæ, are at first free, and moved by cilia; afterwards attached, and budding forth with a plant-like body.1849, W[illiam] H[enry] Harvey, “The Microscopic Wonders of the Sea”, in The Sea-side Book; being an Introduction to the Natural History of the British Coasts, London: John Van Voorst, […], →OCLC...

   Synonyms:

   gemma

   1. (archaic, specifically) A small gemma or bud of dormant embryonic cells produced by some freshwater sponges (phylum Porifera) that develops into a new sponge.
      • Sponges are propagated by gemmules, which originate in the organic mucus, and are carried out of the body by the effluent currents just described. In some sponges these gemmules are ciliated and locomotive when mature; but it seems probable that the majority of the species produce only unciliated...1860, G. J., J. Y. J., “ZOOPHYTES”, in The Encyclopædia Britannica, or Dictionary of Arts, Sciences, and General Literature. […], 8th edition, volume XXI, Edinburgh: Adam and Charles Black, →OCLC...
2. (historical) In the obsolete theory of pangenesis propounded by the English scientist Charles Darwin (1809–1882): a hypothetical particle once thought to be the basis of heredity.
   • […] I assume that cells, before their conversion into completely passive or "formed material," throw off minute granules or atoms, which circulate freely throughout the system, and when supplied with proper nutriment multiply by self-division, subsequently becoming developed into cells like those...1868, Charles Darwin, “Provisional Hypothesis of Pangenesis”, in The Variation of Animals and Plants Under Domestication. […], volume II, London: John Murray, […], →OCLC, part II, page 374
3. Synonym of plumule (“the first bud, or growing point, of a plant embryo, situated above the cotyledons”).
   • To what do this cavity which contains the gemmule, this thin layer which covers it, correspond? We have stated that the cotyledon is nothing else than the first leaf of the little vegetable, and the gemmule the union of the leaves which will follow it.1849, Adrien[-Henri] de Jussieu, “Ovule and Seed”, in James Hewetson Wilson, transl., The Elements of Botany, London: John Van Voorst, […], →OCLC, § 579 (Monocotyledonous Embryo), page 442

   Synonyms:

   plumule

4. Synonym of dendritic spine (“a small membranous protrusion from the dendrite of a neuron that typically receives input from a single axon at the synapse”).
   • Concussion from shell explosion often sufficient to produce miliary hemorrhages in brain substance. Mott has found such lesions in brains of shell shock. Lesser lesions on fine nerve fibrils and gemmules, or nerve cells may reasonably be postulated.1927, William N[ewbold] Bispham, “Professional Schools in Military and Nonmilitary Institutions”, in Frank W. Weed, editor, The Medical Department of the United States Army in the World War, volume...

   Synonyms:

   dendritic spine