GASTRAEA n.
a double-walled sac from which, according to the hypothesis of Haeckel, man and all other animals, that in the first stages of their individual evolution pass through a two-layered structural stage, or gastrula form, must have descended. This idea constitutes the Gastræa theory of Haeckel. See Gastrula.…
GECKO n.
Any lizard of the family Geckonidæ. The geckoes are small, carnivorous, mostly nocturnal animals with large eyes and vertical, elliptical pupils. Their toes are generally expanded, and furnished with adhesive disks, by which they can run over walls and ceilings. They are numerous in warm countries, and a few species ar…
GELATIN; GELATINE n.
, Gel"a*tine (, n. Etym: [F. gélatine, fr. L. gelare to congeal. See Geal.] (Chem.) Animal jelly; glutinous material obtained from animal tissues by prolonged boiling. Specifically (Physiol. Chem.), a nitrogeneous colloid, not existing as such in the animal body, but formed by the hydrating action of boiling water on t…
GEOGRAPHY n.
ation of the earth's surface, of the distribution of land and water, of minerals, plants, animals, etc., and applies the principles of physics to the explanation of the diversities of climate, productions, etc. -- Political geography treats of the different countries into which earth is divided with regard to politica…
GERM n.
ry (bellow). -- Germ cell (Biol.), the germ, egg, spore, or cell from which the plant or animal arises. At one time a part of the body of the parent, it finally becomes detached,and by a process of multiplication and growth gives rise to a mass of cells, which ultimately form a new individual like the parent. See Ovum…