Lyon: OBSERVATIONS ON EMBRYOGENY OF NELUMBO. 649 
The integuments of the ovule keep pace with the growth of the 
embryo and form the thin testa of the seed which lines the thick 
pericarp. 
4. Fate of the Endosperm.—The endosperm reaches its max- 
imum growth early in Stage C when it forms a considerable 
mass of tissue lying between the lobes of the cotyledon (Fig. 
16). The cell walls are never firm and offer little resistance 
to the growing plumule which forces its way into the center of 
the mass. The nuclei soon after begin to disappear and the 
cells to lose their definite outline. The resulting débris is 
crowded around the plumule by the growth of the cotyledonary 
lobes and is apparent in the seed as a colorless structureless 
sheath nearly or quite surrounding the plumule. 
5. The Embryo of the Seed.—A carful study of the embryo 
of the seed without reference to its development brings to light 
many conditions not to be found in a dicotyledonous seed. The 
lobes of the cotyledon are not separate structures, but have a 
common tissue at the base of the embryo upon which the plu- 
mule stands (Figs. 11, 22). The sinuses between the lobes are 
not of equal depth, the front sinus being deeper than the rear, 
so that the common tissue of the lobes (4, Fig. 11) extends 
higher up in the rear of the plumule than it does in front of it. 
This peculiarity is even more noticeable in the seed of JV. 
nelumbo than in that of JV. Zufea illustrated in the figure, and it 
is so distinct that it is remarkable that it has not been described 
before. The radicle is to a greater or less extent imbedded in 
tissue of cotyledonary origin, in this respect conforming to well- 
known monocotyledonous types. 
THE EMBRYOGENY OF NELUMBO COMPARED WITH THAT 
oF OTHER MONOCOTYLEDONS. 
In its early development the embryo of /Velumdo is strikingly 
similar to that of Prstza described by Hegelmaier (’74, 681- 
686. pl. rr. fig. 45-52). The odsperm of Pistza, Hegelmaier 
finds, does not cut off a suspensor cell but by uniform divisions 
builds up a spherical embryoas in Velumbo. The bifurcation 
of the cotyledon is not so inexplicable a deviation from the or- 
dinary course of development as it may at first appear. It is 
rather to be considered as a modification brought about through 
the adaptation of the embryo to the available space within its in- 
vestments. 
