Bui. 183, U. S. Dept. of Agriculture. 
d / 
Plate II. 
Fig. 1 .—Longitudinal (Dorsi-ventral) Section of a Mature 
Barley Grain. 
a, Starch endosperm; b, aleurone layer; c, area of starch endo- 
sperm, adjacent to the scutellnm, representing the initial 
stage of the corrosion of the endosperm. This took place at 
the close of the ripening of the grain, d-r, The embryo; d, 
plumule with investing sheath; c, primary, and e', secondary, 
radicles; /, scutellum, the surface next to the endosperm covered 
■with the epithelial layer (g); r, root cap of primary radicle. 
Fig. 2.— Longitudinal Section of Barley Grain, Showing 
the Stage of Endosperm Conversion at the End of 
the Second Day of Germination. 
Thestarch endosperm is being broken down in thedenseareas directly 
in front of the epitheliallayer, (e), of the scutellum (s), and more 
rapidly in the less dense areas adjacent to the aleurone layer, (a). 
b, Clear fluid area produced during germination; c, corroded area of 
starch endosperm; n, normal starch endosperm not yet attacked. 
