Fig. 3

The rates of survival of ray parenchyma cells, as determined from the current year’s xylem to the annual ring in which all ray parenchyma cells had lost their organelles. An arrow indicates the first observed cell death. The shaded region indicates the intermediate wood. From the twelfth annual ring from the cambium to the pith, the color of xylem was typical of the heartwood of Cryptomeria japonica. The definitions of intermediate wood and heartwood are described in “Terminology” in “Materials and methods”