a.) es See ee et ee aay eae ee 
7 
wn 
STORAGE OF FOOD IN THE SEED .19 
Pulp scraped from a potato, that from a canna rootstock, wheat 
flour, the finely powdered starch sold under the commercial name of 
“cornstarch” for cooking, oat- 
meal, and buckwheat finely pow- 
dered in a mortar, will furnish 
excellent examples of the shape 
and markings of starch grains. 
Sketch all of the kinds exam- 
ined, taking pains to bring out 
the markings.1. Compare the 
sketches with Figs. 7 and 8. 
With a medicine-dropper or a 
very small pipette run in a drop ‘Fie. 7.— Canna Starch. (Magnified 
of iodine solution under one edge sa aa a 
of the cover-glass, at the same time withdrawing a little water from 
the margin opposite by touching to it a bit of blotting paper. 
er es ee SS SEE 
#“SSSGOONNOODD 
n- - SSSESRSSES 
DOOD Oa Oo 
Fic. 8.—Section through Exterior Part of a Grain of Wheat. 
ce, cuticle or outer layer of bran ; ep, epidermis ; m, layer beneath epidermis; qu, 
sch, layers of hull next to seed-coats; br, n, seed-coats ; Ki, layer containing 
proteid grains ; st, cells of the endosperm filled with starch. (Greatly magnified. ) 
’ 1 The markings will be seen more distinctly if care is taken not to admit 
too much light to the object. Rotate the diaphragm beneath the stage of the 
microscope, or otherwise regulate the supply of light, until the opening is 
found which gives the best effect. 
