gemmule
/ˈd͡ʒɛˌm(j)ul/
Frequency: 0.00 in modern English
Meaning
noun
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”)
Archaic
noun
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”)
Archaic
noun
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.
noun
Synonym of plumule (“the first bud, or growing point, of a plant embryo, situated above the cotyledons”).
noun
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”).
Example Sentences
- "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."
- "Accidental hematozoa may be found, […] in the vessels of man and other animals; these are foreign to the blood, and do not circulate with it. The hydatid, acephalocystis endogena, detaches its gemmules from its inner surface; one thus inclosing the other in a series, like pill-boxes. It is found in the liver, kidney, womb, etc."
- "They [spores and tetraspores] may rather be considered, the one a true spore, supposed to be fertilized by means of an antheridium; the other, a mere gemmule, or bud of the simplest possible structure, which is cast off by the parent plant, and carries with it sufficient vitality to become the nucleus of a fresh individual."
- "The gemmules of the Marchantia [a genus of liverworts] are little disc-shaped masses of cells composed of two or more layers."
- "The ova [of the brown hydra, Hydra oligactis, formerly Hydra fusca] covered with a horny substance possess a great power of resistance to the cold, thus preserving their vitality until the return of conditions favorable for their existence, when development begins to take place. This proceeds up to a certain point, the covering of the ovum bursting, liberates the embryo, which becomes ciliated, and for some time swims freely in the water; in this condition it is known as a "gemmule.""
- "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 gelatinous grains, which are nevertheless endowed with a very active motility, like the ultimate particles of even inorganic matter."
Etymology
Origin
- Source language: French
Word Breakdown
Regional Pronunciation
- American English: /ˈd͡ʒɛˌm(j)ul/
- British English: /ˈd͡ʒɛmjuːl/
Usage
Subject
Wiktionary places this term in Medicine.