Galls

Galls (when large, dry, and nut-like often called GALL-NUTS, also Nut-galls and Oak-apples) are the abnormal vegetative growths produced in various plants through the introduction of the eggs, and the development of the larvæ of the various gall-insects. The economic usefulness and consequent commercial importance of so many of the larger forms, essentially due to the presence of a large quantity of tannic acid, is noticed at TANNIN. See also GALL-FLY, GALLIC ACID, LEATHER.