208 BOTANICAL GAZETTE [SEPTEMBER 
ledons forces the base of the embryo backward, so that both coleo- 
rhiza and suspensor are crushed little by little to a flat, brown disk 
(figs. 4, 5). Further elongation forces the base of the embryo 
through the softer, micropylar portion of the seed coat; figs. 6, 7, 8 
show this and the two succeeding stages. In jig. 7 the base of the 
cotyledon is curved downward, and the plumule is seen issuing from 
between its opened edges; and it may be observed that this method 
of development has thrown the first leaf out of alignment. The 
edges close in again, and remain adhering the full length of the coty- 
ledon (fig. 13). The tip is sometimes lobed (figs. 14, 15). 
The cotyledon always develops on the lower side of the embryo 
as the seed lies during germination. In seedlings which were turned 
after the cotyledon had begun to develop, the plumule has not suc- 
ceeded after a year in emerging from underneath the cotyledonary 
sheath with which it is hampered. 
Fig. 8 shows the appearance of the tardy root, which has made its 
way through the brown cap formed from the remains of the disorgam- 
ized coleorhiza and suspensor. When the root pierces the soil, the 
starch is transferred to it from the endosperm, and the root thickens into 
a tap root. By its further penetration into the soil, it often draws 
the upper portion further down, imbedding the seed, and possibly 
giving to the first series of lateral roots their initial upward slant. 
The lateral roots almost always appear in threes, whether the root 
be tetrarch or triarch. Fig. g represents a seedling toward the 
close of this period of its activity. The extreme shortness of the 
hypocotyl may.be conjectured from the small distance betwee? the 
base of the cotyledon and the insertion of the first whorl of lateral 
roots. The plumule is composed in this case of two brownish, hay 
scales, enclosing a foliage leaf with circinate vernation (#ig- 7 a 
Each scale is terminated by a sharp, curved point. The number ¢ 
scale leaves varies in different seedlings; some have only one, and in 
in some few observed the first organ was a perfect foliage leaf, 
base of both scale leaf and foliage leaf is furnished with broad, WS 
like expansions which enclose the next leaf. The petiole of the first 
leaves reaches a length of 15~20°™, and bears one or two pairs 
pinnae inserted near the adaxial face. Between the two erminal : ms 
pinnae there is a tiny, sharp spine, which has its counterpart 1? 
