Prunus. Fig. 2.—Longitudinal tangential section of inner bark of Prunus serotina.

Fig. 2.—Small portion of longitudinal section made well toward the cambium zone and parallel to it. Magnification about 75 diameters.
a, crystal of calcium oxalate;
b, a medullary ray cell containing starch;
c, sieve tube;
d, medullary cell.

This image is from Structure of our Cherry Barks in the September issue of the American Journal of Pharmacy, 1895.