48 
PHARMACEUTICAL BOTANY 
aniline dyes. They contain a more or less distinct highly refractile 
point of origin or growth called the “ hilum,” which also takes the 
stain of an aniline dye. The layers of carbohydrate material stain 
variously, blue, indigo, purple, etc., with different strengths of 
iodine solutions. Each grain is covered with a stainable elastic 
membrane. 
Fig. 15. — Cell of Pellionia Daveauana, showing starch-grains. The black, 
crescent-shaped body on the end of each grain is the leucoplast. Greatly enlarged. 
(Gager.) 
Starch grains may be grouped, according to the condition in which 
they are found in the cells of storage regions into three kinds, viz.: 
simple starch grains, compound starch grains and fill starch grains. 
Simple starch grains are such as occur singly. Compound starch 
grains occur in groups of two, three, four, five, six or more and are 
designated as two, three, four, five, six, etc., compound, according 
to the number of grains making up the group. Fill starch grains 
are small grains filling up the spaces between the larger grains in 
storage cells. These are common in commercial starches. 
Method of Examining Reserve Starches.- — Many of the reserve 
starches are used commercially, such as potato, corn, rice, maranta, 
oat, wheat, sago, tapioca, etc., and it frequently becomes necessary 
for the microscopist to determine their purity or their presence in a 
