Fig. 334, 335, 336. Microscopic structure
of transverse sections of the barks of C. calisaya, C. scrobiculata, C. pubescens.
cc, Cellular tissue of the liver.
ee, Cellular envelop.
fl, Fibres of the liber (i.e. cortical fibres).
l, The liber.
pd, A portion of the periderm attached to the liber.
s, Suberous coat.
This image is from _ in Pereira's Elements of Materia Medica and Therapeutics, 1854.