Fig. 19. Transverse sections of peach bark boundary zone tissues examined with  transmission electron microscopy (bar = 1 micron). Fig. 19 shows shared cell wall of two adjacent cells in the boundary zone 12 days postwounding. The compound wall (CW) is very electron dense. Suberin linings (S) are of uniform thickness within individual cells and vary in thickness among cells. Note the fine light and dark lamellations of the suberized wall and the cytoplasmic debris (CD) appressed to the wall of the upper cell.