262 
The Ohio Naturalist. 
[Vol. VIII, No. 4, 
plasmic in appearance but rather consist of a radial arrangement 
of ordinary cytoplasm. They do not lead to cell formation 
although a small amount of endosperm persists until the seed is 
nearly mature. 
After fertilization the egg elongates and forms a pro-embryo 
four cells in length. There seems to be a more or less constant 
transverse division in the second cell of the pro-embryo, thus 
foreshadowing the massive suspensor (Figs. 8 and 9). The two 
suspensor cells thus formed by division together with the basal 
cell flatten against the wall of the integuments and give a foot¬ 
like appearance to the base of the suspensor, and form a hausto- 
rium like organ which maintains its activity, judging by its 
staining reaction, till the embryo is mature, although the upper 
cells of the suspensor may begin to break down before that time 
(Figs. 10, 12, 16 and 17). This organ burrows its way into the 
integuments until it reaches the testa forming a ball of tissue 
which may, apparently from the division of the original three, 
consist of a number of cells. The third cell of the pro-embyro 
probably forms the remainder of the suspensor consisting usually 
of three tiers containing one or two rows of cells (Figs. 13-16). 
The suspensor is rather short, forms no part of the embryo, has 
no hypophysis as has long been known for Geranium,* nor does 
it form the rootcap. As the embryo matures the dermatogen 
and calyptrogen are extended around the tip of the hypocotyl. 
The calyptrogen and calyptra are differentiated from this in the 
usual way. With advanced growth they completely surround 
the hypocotyl and form the root cap (Figs. 15 and 16), which is 
for a time distinctly concave at its junction with the suspensor 
till that organ disintegrates and disappears. With this excep¬ 
tion, the general development of the embryo is similar to the 
Capsella type. The cotyledons arise from the opposite points of 
the almost spherical embryo in the usual dicotyl manner with the 
plumule between them. 
SUMMARY. 
1. The archesporium is a single sub-epidermal cell and 
becomes the functional megaspore directly without forming 
parietal tissue. 
2. The whole nucellus functions as tapetum. 
3. The antipodals and svnergids disappear soon after 
fertilization. 
4. The embryo forms no hypophysis. 
5. A multicellular haustorium-like organ is formed from the 
basal cells of the suspensor which forces its way through the 
integuments until it reaches the testa. 
* Coulter and Chamberlain, Morphology of Angiosperms. 200. 1903. 
