ALSTONIA SCHOLARIS, 



ALSTONIA SCHOLARIS is found in India, in the tropical 

 islands and in Northern Africa. 



It is a handsome forest tree from 50 to 80 feet in height, having 

 a tall slender trunk with spreading branches that always grow in 

 whorles. The leaves are also found in whorles of from five to 

 seven, (fig. i). They are nearly sessile, four to eight inches long 

 and lanceolate or oblong with bluntly acuminate ends. The midrib 

 is prominent on the lower surface, with numerous parallel, trans- 

 verse veins. They are of a bright green color on the upper surface, 

 but pale and dull on the lower. The tree flowers twice a year, in 

 March and December. 



DESCRIPTION OF THE BARK. 



The medicinal part of the tree is the bark. This is found in 

 the market in irregular pieces from ^ to % an inch in thickness 

 and of a spongy texture. The external surface is rough and uneven 

 and of a grayish-brown 1 color, with numerous cream-colored patches 

 that flake off like scales. The inner surface is mealy in consistency, 

 and of a bright yellow color. It is of no particular odor, and its 

 taste is purely bitter, neither aromatic nor acid. 



MICROSCOPICAL STRUCTURE. 



The outer layer of the bark is composed of from eight to 

 twenty rows of tabular parenchyma. The cells are thick walled 

 and empty (see a, fig. 3). The cellulose of the walls is colored a 

 deep amber. As a dividing line between this structure and the next, 

 that is, between the outer and middle layers of the bark, is 

 found a delicate texture, consisting of three or four rows of clear 

 white empty cells (</, fig. 3). This outer layer is called the cortical 

 layer by some authors. 



The middle layer of the bark, which is the principal part of the 

 whole specimen in bulk (/>, figs. 2 and 3), is composed of loosely 



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