In this, too, the art of inoculating[1] took its rise. By the aid of an instrument similar to a shoe-maker's paring-knife an eye is opened in a tree by paring away the bark, and another bud is then enclosed in it, that has been previously removed with the same instrument from another tree. This was the ancient mode of inoculation with the fig and the apple. That again, described by Virgil,[2] requires a slight fissure to be made in the knot of a bud which has burst through the bark, and in this is enclosed a bud taken from another tree. Thus far has Nature been our instructor in these matters.