Prunus. Fig. 5.—Cross section of stem bark of Prunus Mahaleb.

Fig. 5.—Cross-section of bark of Prunus Mahaleb magnified about 75 diameters.
a, cork exfoliating from exterior surface;
b, secondary cork formation farther interior;
c, fissure in cortex;
d, primary bast fibres in outer portion of bast layer;
e, compressed sieve tissue;
f, single bast fibre. (A few scattered bast fibres occur in the secondary bast in this species.)
g, medullary ray;
h, compressed sieve tissue;
i, newly formed bast;
k, cambium zone;
l, large duct in newly formed wood;
m, wood of previous season.

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