STORAGE OF NOURISHMENT IN THE SEED. 235 
in the seeds in bulk, but that it is inclosed in little chambers or 
cells.1 
BICPLDS) 
== === 
Fig. 11.—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 true seed-coats; br, n, seed-coats; K/, layer containing 
grains of proteid material; st, cells of the albumen, filled with starch. 
32. Absorption of Starch from the Cotyledons. —Examine with the 
microscope, using a medium power, 
soaked beans and the cotyledons from 
seedlings that have been growing for 
three or four weeks. Stain the sec- 
tions with iodine solution, and notice 
how completely the clusters of starch- 
grains that filled most of the cells of the 
unsprouted cotyledons have disappeared 
from the shriveled cotyledons of the 
seedlings. A few grains may be left, Fic. 12.—Corroded Starch-Grains 
but they have lost their sharpness of fm the Endosperm of the Kernel 
: of Sprouted Indian Corn. The 
outline, and resemble somewhat the seedling over three inches high. 
‘‘corroded’’ starch-grains of Indian ‘The middle starch-grain of the 
corn shown in Fig. 12: lower row is uncorroded. 
1 The teacher will do well to sketch with the camera lucida a few divisions of the 
stage-micrometer and some cells of the seed, with contained starch-grains, on a piece 
of cardboard that may be passed round the class to give a precise idea of the actual 
and the apparent size of the objects examined. 
