VEGETABLE CYTOLOGY 
51 
Cassava Starch ( Manihot 
utilissima ) 
Grains rounded, truncated on one 
side. 
Simple or two- to three- or four- to 
eight-compound. 
6 to 35 m in diameter. 
Hilum: central, circular or triangu- 
lar with radiating clefts frequently. 
Lamellae: indistinct. 
Polarization cross prominent. 
Leguminous Starch 
Ellipsoidal or reniform-shaped simple 
grains. 
50 to 100M in length. 
Hilum: central, elongated with 
branching clefts. 
Lamellae: distinct, concentric. 
Polarization crosses shaped thus,^ 
Canna Starch ( Canna edulis and other 
species of Canna) 
Broadly elliptical, flattened, with 
beak or obtuse angle at one end. 
50 to 1 3 5 m in length. 
Hilum: excentric near narrower end. 
Lamellae: concentric and excentric. 
Polarization cross very distinct; fine 
plav of colors with selenite plate. 
3. Inulin. — Inulin is a carbohydrate isomeric with starch which has 
the chemical formula of C12H20O10. It is found dissolved in the cell 
sap of many plants, especially those of the Composite. If pieces of 
a plant part containing this substance be placed directly in alcohol 
for at least a week, then sectioned and mounted in alcohol, sphaero- 
crystals of inulin will be seen applied to the walls of the cells. When 
these sections are treated with a 25 per cent, solution of alpha 
naphthol and 2 or 3 drops of strong H2SO4, the sphaerocrystals will 
dissolve with a violet color. Fehling’s solution is not reduced by 
inulin. 
4. Hesperidin. — Hesperidin is a glucoside having the chemical 
formula of C21H26O12. Like inulin it occurs in solution within the 
cell sap. It is found in abundance in the Rutaceae family but occurs 
in many other plants. If sections of alcoholic material containing 
this substance such as Buchu leaves or unripe orange peel, are 
mounted in alcohol and examined, sphaerocrystals will be seen. If 
these are then treated with a drop of alpha naphthol solution and 2 
or 3 drops of strong H2SO4, they dissolve with a yellow color. The 
same coloration is evident when 5 per cent, solution of KOH is 
substituted for the alpha naphthol and H2SO4. 
5. Strophanthin. — This is a glucoside occurring in the cell sap of 
the endosperm of Strophanthus Kombe, S. hispidus and other species 
of Strophanthus. If sections of fresh Strophanthus seeds are 
mounted in a drop of water and then transferred to a drop of con- 
