( 336) 
EMBRYO-SAC 
Fevillea 
The first indication of the appearance of the ovules upon 
the placental folds may be noted at the time when the young 
pistillate flower is slightly less than 1 mm. in length. Slight 
elevations along the reflexed margins of the carpels indicate 
the positions of the individual ovules. At this time the 
whole placental region shows distinctly the characteristics of 
meristematic tissue. As Warming® has shown, the growth 
of the ovular ‘* Anlage” proceeds by the division of subepi- 
dermal cells, and he has pointed out that in some these divi- 
sions occur chiefly in those cells situated immediately below 
the epidermis, and in others in the third layer of cells, or the 
second below the epidermis. Among the Sympetalae the 
former type is represented by Sexeczo, the latter by Symphy- 
tum, Verbascum, Lamium and others. A section through 
the ovary of a very young flower of Fevzllea, before there is 
any indication of the formation of ovules, shows that the 
multiplication of cells is chiefly in the region several layers 
of cells deep under the epidermis. There are no very regu- 
lar subepidermal layers of cells at this period, divisions occur- 
ring in different planes. The divisions, however, predomi- 
nate in the plane tangential with reference to the ovary wall, 
so that the central region of the placenta shows radiating 
rows of cells which flex to right and left toward the borders 
from which the ovules arise. When, however, the formation 
of ovules begins to be evident, a layer of subepidermal cells 
of considerable regularity is noticeable, and divisions occur 
abundantly in this layer as well as in the epidermis in a radial 
direction. Sometimes the second and third layers assume a 
degree of regularity, all of which is merely an expression of 
the direction of growth at this time. The subepidermal layer 
remains distinct for some time while divisions of its cells are 
taking place in radial planes. Even after tangential walls are 
formed in these cells, the limits of the original subepidermal 
layer are still apparent in the older and thicker walls which 
