I now observed what at first appeared to be the hind leg of the farther side of the body protruding beneath, but in another moment noted my error, and saw that its sharp point had penetrated the bark, into which it soon sank quite deeply, and I realized that the ovipositor was now conducting its tiny eggs into the cambium layer of the bark.
"My Studio Neighbors"
William Hamilton Gibson
Or this last form is modified by making a long sloping cut from the bud to the upper end, thereby exposing the maximum amount of cambium.
"Manual of American Grape-Growing"
U. P. Hedrick
The essentials may be set forth in three statements: First, the prime essential is that the cambium layers, the healing tissue lying between the bark and wood, meet in the cion and stock; second, that method of grafting is best in which the cut tissues heal most rapidly and most completely; third, the greater the amount of cambium contact, as compared with the whole cut surface, the more rapidly and completely the wounds will heal.
"Manual of American Grape-Growing"
U. P. Hedrick