Si8, BOTANY AND PHARMACOGNOSY. 



the ROOT BARK is employed for the extraction of the alkaloids, 

 especially quinine. Owing to the fact that light seems to influ- 

 ence the production of quinine in the plant, a larger amount being 

 produced in the root bark and also in the stem bark if excluded 

 from the light, it is now customary to cover the bark of the trunk 

 with moss, leaves and other protecting materials. The bark col- 

 lected from trees treated in this manner is known as " mossed 



Fig. 226. Commercial cinchona barks: i, 2, 3, red cinchona with transverse fissures; 



4, 5, red cinchona, the former with longitudinal furrows; 6, 7, Loxabark (Cinchona pallida); 



5, flat bark ^Cinchona calisaya). About J actual size. 



BARK." At the present time cultivators remove the bark from the 

 trunk in alternate strips, the denuded places being again covered, 

 after which another layer of bark develops that is very rich in 

 alkaloids and is known as " renewed bark." The outer bark, con- 

 sisting of the periderm layer and some of the cortex, is flattened 

 out and allowed to dry under pressure, and constitutes the " flat " 

 (or Tambla) bark (Fig. 226). 



