the Seed in the A Isinoideae. 
43 
is densely filled with starch contents (Fig. 25, c.), the small cells of 
the root cap (Fig. 25, r. r.), succeeded by the enveloping layer of the 
endosperm cap cells (Fig. 25, end. c.) which present an actively secretory 
appearance and are connected as one tissue with the root of the embryo on 
one side, and the nucellus on the other. A section taken above the root cap 
still shows the endosperm cap cells (Fig. 26, end. c.), but in a section through 
the hypocotyledonary portion they are no longer seen (PL VI, Fig. 28). 
The second stage in germination which occurs in a day or two 
according to the temperature and amount of moisture present, is marked 
by the apical portion of the endosperm being pushed slightly through the 
micropyle by the root apex on the elongation of the hypocotyl (PL VI, 
Figs. 31 and 32, end. c.). It is ruptured immediately (Fig. 33, end. c.) as the 
root grows through it, but the extruded portion which invests the hypocotyl 
as a collar persists on the seed coat after the cotyledons have been with- 
drawn (Fig. 35, end. c.). The basal portion remaining in the ovule is fused 
to the nucellus (Fig. 29, end. c.). 
The cells of the ruptured endosperm cap lose contents and become 
vacuolated, they also elongate in a lateral direction (PL VI, Fig. 30, end. c.), 
but remain in connexion with the few strands of much compressed and 
empty axile cells which form the remains of the nucellus (Fig. 29, end. c. 
and ax. c.). The hypocotyl elongates with extraordinary rapidity and the 
development of root hairs being more or less simultaneous with the rupture 
of the endosperm cap (Figs. 33, 34, r. hi). In one case they were formed 
when the root was still in the micropyle. These facts seem to point to the 
conclusion that once water absorption can take place the embryo is 
independent of the ovule, though the whole cotyledonary portion may be 
still enclosed in the seed coat, for it can then utilize the starch which has 
been transferred to its tissues during germination. 
The cotyledons have no connexion with the food reserves of the ovule. 
The epidermal layer is cuticularized on germination, when it reacts to 
iodine and sulphuric acid. Stomata appear on the dorsal and ventral 
surfaces as the hypocotyl emerges (Fig. 41). Air spaces occur in the meso- 
phyll and a thread-like system of vascular strands pervades the lamelli of 
the cotyledons (Figs. 39 and 39 a , fra.). 
These strands terminate below the apex of the lamelli in two pencil 
ends of tracheides which lie under a well-marked epithem composed of 
loose cells, large water stomata occurring in the epidermis on the dorsal 
side (Fig. 42, w. sto.). 
In some cases where seeds were germinated in the dark with excess of 
moisture these stomata were more numerous, the epithem better developed, 
and the tracheids in greater number and more diffused. 
The epithem region shows differentiation in the mature embryo, 
staining lighter than other portions. On germination it remains free of 
