CINCHONA 633 



are the more prominent. The secretory elements are of a number of 

 forms: (a), glandular hairs, consisting of several rows of cells, may 

 occur on the stipules; (6), the epidermal cells occasionally contain a 

 resinous secretion: (c), cells containing resin are sometimes present in 

 the mesophyll; (d), secretory cells containing a brownish content are 

 found in the leaves of a number of genera and are probably widely 

 distributed; (e), elongated secretory sacs have been observed in 

 Cinchona, Cascarilla, and other genera; and finally (/), a group of 

 secretory cells tending to form internal glands. The fibrovascular 

 bundles are collateral; the walls of the tracheae have either simple 

 pores or scalariform perforations; and the wood fibers usually possess 

 bordered pores, occasionally simple pores.. Calcium oxalate is 

 secreted in a great many different forms, including rosette aggre- 

 gates, sphenoidal microcrystals, small acicular crystals, raphides and 

 styloids, occasionally in the form of large rhombohedra, or crystal 

 fibers. The subsidiary cells of the stomata are arranged parallel to 

 the pores. Non-glandular hairs are either unicellular or uniseriate. 

 External glandular hairs are wanting. 



CINCHONA. Cinchona Bark. The dried bark of the stem and 

 branches of various species of Cinchona (Fam. Rubiacese), trees 

 indigenous to South America, and cultivated in the East Indies, 

 Jamaica, Mexico and the Portuguese possessions in northwest Africa 

 and from which countries the commercial supplies are obtained. 

 There are two principal commercial varieties: (1) RED CINCHONA, 

 which is yielded by Cinchona succirubra, and its varieties, trees 

 indigenous to southern Ecuador and northern Peru; and (2) CALISAVA 

 BARK or yellow Cinchona, yielded by Cinchona Calisaya and its 

 varieties, trees indigenous to Peru and Bolivia, and also obtained 

 from C. Ledgeriana, a tree indigenous to Bolivia and cultivated in 

 Java and the British Indies. When the trees are from 6 to 9 years 

 old they possess the maximum amount of alkaloids and the bark of 

 the trunk as well as the roots is removed and allowed to dry. The 

 bark of the stem is used in the manufacture of galenicals, while the 

 root bark is employed for the extraction of the alkaloids, especially 

 quinine. Owing to the fact that light influences the production of 

 quinine in the plant, it was formerly customary to cover the bark of 

 the trunk with moss or other materials, and this is known as " mossed 

 bark." For a time the cultivators followed the practice of removing 

 the bark in alternate strips from the trunk, the denuded places being 

 again covered, after which another layer of bark developed, very 

 rich in alkaloids and known as " renewed bark." The outer bark, 

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



