Gemmules

GEMMULES (diminutive from Latin gemmae - bud): 1) Buds that form inside the bodies of sponges, consisting of parenchymal cells usually surrounded by a special capsule and skeleton. The formation of G. in our freshwater sponges (Spongilla) is associated with the onset of autumn and winter, while in tropical sponges it is associated with the onset of drought. The sponge itself dies in this process, and only within the G. do living cells persist, which, when favorable conditions return, emerge through an opening in the capsule and form a young sponge. It is possible that the formation of G. is not necessarily connected with surviving unfavorable seasons, since gemmule-like structures have also been found in marine sponges. 2) G. are also called the smallest particles or rudiments which, according to Darwin's hypothesis of pangenesis, separate from each cell of the body, spread throughout the organism, and even multiply through division. According to Darwin's concept, these G., collecting from all parts of the organism in the sexual elements, accumulate there and, developing, in the next generation finally give rise to cells similar to those from which they once separated. Thus, strictly speaking, reproduction is carried out not by sexual elements, not by buds, but by all cells that make up the organism. These assumptions constitute the essence of the hypothesis of pangenesis, which Darwin attempted to explain the inheritance of acquired characteristics (e.g., through exercise) and the phenomena of asexual reproduction and regeneration.