67 



4. Hilum. Distinct, in small end. Excentricity usually 



1-3— 1-6. 



5. Polarization Crosses. Very distinct, striking. 

 G. Selenite Plate. Fineplay of colors. 



C CANNA. 



1. Size. Grains usually 5(V — lOO long, occasionally larger. 



2. Form. Flattened, — ellipsoidal. Obtusely angled at one 



end. 



a. No aggregates. 



3. Laminae. Distinct, striking. 



4. Hilum. Distinct, circular. 



a. Within obtuse angle. 



b. Excentricity 1-5 — 1-7. 



5. Polarization Crosses. Remarkable, distinct. 



6. Selenite Plate. Beautiful play of colors. 



D TUMERIC. 



1. Size. Grains usually 40 — SO/i long. Seldom larger. 



2. Form. Clam shaped, ovoid. 



a. Often in loose aggregates. 



b. Starch lumps yellow. 



1 . Become crimson with H2SO*. 



3. Laminae. Very distinct. 



4. Hilum. Visible. 



5. Polarization Crosses. No appreciable crosses. 

 C. Selenite Plate. No play of colors. 



E SAGO. 



1. Size. Grains occur in two sizes; the larger 30 — Qbn 



long, the smaller 20ai and less in length. 



2. Form. Very irregular. 



a. Ovoid, segmented-ellipsoidal. 



b. Aggregates of one large and two small 

 grains often present. 



1. Contact surfaces (facets) not 

 adjacent. 



3. Laminae. Distinct. 



