242 
Fia. 137.—Germination of In- 
dian Corn. J, I, III, succes- 
sivestages. 4 and B,frontand 
side views of a separated em- 
bryo; w, root; e, part of seed 
filled with endosperm: sc, co- 
tyledon; 7, its open margins; 
b, b’, b”’, leaves of young plant; 
1, fragment of wall of ovary. 
Natural size. . 
BOTANY. 
leaves is for the most part such that 
the veins run more or less parallel 
to one another, and when they 
join each other enclose four-sided 
spaces; rarely, however, their veins 
are irregularly distributed and 
form an irregular network, 
512. The germination of Mono- 
cotyledons may be illustrated by 
the Indian corn. Here the embryo 
lies partly imbedded in one side of 
the large endosperm (Fig. 136). 
The first leaf of the young plant 
(the cotyledon, or scutellum), se, 
has its broad dorsal surface in con- 
tact with the endosperm; anteriorly 
it is curved entirely around the re- 
mainder of the embryo. 
513, Under proper conditions 
the main root pushes through the 
root-sheath (ws, Figs. 136, 187). 
The plumule, consisting of a mi- 
nute stem and a few rudimentary 
leaves, next pushes out through 
the upper end of the curved co- 
tyledon (ZZ, Fig. 137). The co- 
tyledon remains in contact with 
the endosperm and absorbs nour- 
ishment from it for the sustenance 
of the growing parts. Lateral 
roots soon appear upon the main 
root, and adventitious ones arise 
