156 BOTANICAL GAZETIE [ancy 
the simpler monocotyledons hitherto investigated, the ovule is 
axial in origin. 
The early history of the embryo-sac could not be traced, but 
as the mature sac, at the time of fertilization, corresponds closely 
with that of the typical angiosperms it is not likely that ther 
are any marked peculiarities in its early development. | 
In the mature ovule (figs. z, 2) the broad apex of the embryo 
sac is covered by two layers of cells, the outer ones bei 
elongated so that the apex of the nucellus is pointed. The cyto 
plasm is confined to an extremely thin layer lining the wall, and 
a small amount surrounding the polar nuclei. The egg-apparatls - 
is relatively small but offers no especial peculiarities. The syntr 
gide (fig. 2,5) are smaller than the egg (0), and their cytoplasm 
is densely granular, whereas the egg appears almost transparellt 
The nuclei of the synergide are small, but distinct, and like that 
of the egg, they possess a conspicuous nucleolus. The nuclets 
of the egg is somewhat larger than the nuclei of the synergide, | 
but otherwise resembles them. 
On examining the antipodal region of the embryo-sac (fg3) 
the very small size of the antipodal cells (am) is at once notice: 
able; indeed, where these have collapsed in the proce a 
~ embedding, it is almost impossible to see them at all. 
The polar nuclei are much larger than the other nucle! oft 
embryo-sac, and probably always fuse before fertilizatio® ® 
effected. This, however, has not been positively shown. In 
Specimen shown in fig. 3, the fusion of the polar nuclei wa 
plete, and the single large endosperm-nucleus (em) was ese’ 
spicuous. In the embryo-sac of S. Greenit, however (ag . 
Jig. 4), the two polar nuclei were clearly distinguishable, alt 
they were in close contact. | 
The actual fertilization has not yet been observed, and = 
to the small size of the nuclei of the pollen-spore and p? * 
tube, it is not likely that this will be easy to demonstrate * 
factorily. 
As usual, the synergide disappear after fertiliz 
ation, and ‘ 
egg-cell, now become the one-celled embryo (fig: ee. 
em); 
