Online Dictionary of Invertebrate Zoology: Complete Work - Best Text

Online Dictionary of Invertebrate Zoology 397germ tract The complete detailed history of the germ cellsfrom one generation to the next.gerontic a. [Gr. gerontos, old man] Pertaining to decadence;old age; deteriorating.gerontogeous a. [Gr. gerontos, old man; ge, earth] Belongingto the Old World or Eastern Hemisphere. see neogeic.gerontology n. [Gr. gerontos, old man; logos, discourse] Thestudy of aging.gerontomorphosis n. [Gr. gerontos, old man; morphe, form]Evolution involving specialization and diminishing capacityfor further evolutionary change.gestation n. [L. gestare, to bear] In viviparous animals, theperiod from conception to birth.geusid n. [Gr. geusis, taste] (NEMATA) Gustatory organ.giant bud (BRYO: Gymnolaemata) Unpartitioned distal endgrowth in which the side walls grow faster than the internaltransverse walls.giant cell A term applied to a host response in which a multinucleatemass of protoplasm or cytoplasm often acts as apreferred feeding site or "nurse cell". see coenocyte,syncytium, lysigenoma, teratocyte.giant chromosome (ARTHRO: Insecta) In Diptera, a very largechromosome bundle that arises by repeated endoreplicationof single chromatids.giant fiber Enlarged nerve fibers that transmit rapid impulsesin certain mollusks, crustaceans, annelids, pogonaphoransand insects; giant fibre.gibber n. [L. gibbus, humped] A swelling or enlargement; arounded protuberance.gibbous, gibbose a. [L. gibbus, humped] Very convex; humpbacked;embossed; swollen; a protuberance.Gicklhorn's organ (ARTHRO: Crustacea) In Copepods, pairedphotoreceptors having two cells that closely resembleretinula cells, found in proximity to the frontal eye.gigantism n. [Gr. gigas, giant] Excessive growth of an organor a complete organism to a large size.