Gall

a morbid excrescence on the leaf or leaf-bud of any plant, arising probably from the puncture of a cynips. In the hole made by the insect, an egg is deposited, in due time to be developed into a larva, which eats its way out_when it comes to the perfect state. One variety is white or 9 another green, gray, or black. The best galls come from Smyrna and Aleppo. With the salts of iron they should yield a fine black color, and are used in the manufacture of ink. Gall-nuts are useful on account of the tannin and gallic acid contained in them.