ANDERSON: EMBRYOGENY OF MARTYNIA LOUISIANA 155 
cotyledons (C) are very large and fleshy. This figure shows 
also a little endosperm which, in the mature seed, comprises 
a thin, transparent covering for the embryo. The embryo has 
developed in such a way that it practically fills the lower part 
of the sac, while the upper and middle portions (Q) form in the 
mature seed a little brown tube on the micropylar end of the 
remaining endosperm. There is also a small brown knob at 
the chalazal end (K) marking that part of the embryo-sac for- 
merly occupied by the large antipodals, the remains of which 
appear at N. The broken line in this figure represents the 
demarcation in the tissue forming the seed coat. That region 
of tissue next the endosperm (V) matures into the soft inner 
portion of the seed coat, while the walls of the cells forming the 
outer portion (W) become thick and lignified, thus maturing 
into a hard warty exterior which becomes very dark brown or 
black in color. 
SUMMARY 
The flowers develop in the axils of protective bracts. The 
cycles of the flower appear in the following order: calyx, corolla 
and epipetalous stamens, and pistil. 
Of the four potential megaspores formed, only one is function- 
al. 
The embryo-sac is long and narrow, with the micropylar end 
considerably enlarged. The large egg-cell extends far down 
into the sac cavity, with the two synergids on either side. The 
three antipodals are long, slender cells that increase in size and 
persist as elaborators of food. 
he polar nuclei move to a position near the center of the 
sac where they unite before the pollen tube reaches the ovule. 
Fertilization usually occurs within six to eight hours after 
pollination. 
The rather large pollen tube stains densely throughout the 
greater part of its length and persists in the micropyle and upper 
end of the embryo-sac long after the endosperm is formed. 
The first division of the endosperm cell, which is usually 
transverse, occurs before. fertilization. At first, a few cells 
are formed in the upper and middle portions of the embryo-sac, 
but the bulk of the endosperm is in the lower part of the sac, 
where the embryo develops. 
The suspensor is very long and narrow and pushes the embryo 
