ALSTONIA SCHOLARIS. 97 



inner bark, though they do not disappear entirely. Many of the 

 cells of the middle bark contain beautiful crystals of calcium oxa- 

 late. Found much more numerous toward the outer edge (/, fig 

 3). Some of the cells are enlarged and filled with oil or the essen- 

 tial properties of the plant. 



We find the inner layer of the bark is narrow and composed of 

 thin walled, irregularly packed cells, with occasionally an oil gland. 

 The inner part of the bark is traversed by waving medullary rays, 

 loaded with minute starch grains. A longitudinal section of the 



Fig. 2. Cross Section of Dita Bark. Three times its Natural Size. 

 a, Outer Bark, b, Middle Bark, c, Inner Bark. 



middle layer gives a few 7 large laticiferous vessels, which contain the 

 latex or the concrete juice of the tree in brownish masses. 



HISTORY. 



Alstonia Scholaris was first described and illustrated by Rheede 

 in 1678. Although its praises were sung by the poets before the 

 Christian era, according to Dr. Rice, who found some ancient Sans- 

 krit epic poetry on the subject of Alstonia. In 1841 Rumphius 

 again describes the tree and gives the probable origin of the name 

 Scholaris. It seems the school children used to make slates from 

 the close-grained wood of this tree, making the letters on the slab 

 with sand. The plant is named Alstonia in honor of Charles Als- 

 ton, Professor of Botany and Materia Medica in the University of 

 Edinburgh from 1740-1760. It was named Echitcs Scholaris by 

 Linnreus. The common name among the island natives where it is 

 found is Satween. In the Philippines and to some extent in the 

 United States, it is known as Dita Bark. It is also called the "devil 

 tree" and Palimara of Bombay. 



The drug is officinal in the Pharmacopoeia of India. It is not 

 employed to any extent in Europe, and is not recognized in either 



