14 BOTANICAL GAZETTE [JULY 
In the axil of the sporophyll two swellings are present, the sec- 
tion passing longitudinally through one of them. These are 
the rudiments of the ovules which by January 4 (fig. 33) have 
begun to show the first indication of an integument. Fig. 34 
shows a sporophyll collected in Baltimore March 11. The ovule 
has increased in size and the nucellus and integument are of 
equal height. It seems that slow growth is continued all through 
the winter months whenever the condition of the weather will 
permit. A few weeks before the time of pollination, the placen- 
tal outgrowth begins to appear as slight projections between 
and at the sides of the sporangia. By April 8 (fig. 36) the 
cushion has begun to show between ovule and scale, and by 
April 22 (jig. 37) it has reached a considerable size. The fur- 
ther development of the sporophyll is almost entirely confined 
to its basal part where cushion and scale are indistinguishable, 
and to the great extension of the cushion above and sidewise 
as a protective covering to the ovules. The tip above the cush- 
ion remains small and is soon much surpassed by the latter, 
which by fusing with the scale above soon comes to inclose com- 
pletely the cavity in which the ovules lie. The outgrowths are 
not confined to the ovule-bearing scales, but are developed in 
almost as great degree in the axils of the adjoining scales below 
and at the tip. The number of fertile scales is usually about 
ten. They are bounded beneath and above by scales differing 
- from them only in the absence of ovules. As the growth pro- 
ceeds, the area of attachment of the ovules to the scale becomes 
much greater in extent, so that when the seed is mature almost 
the whole of its outer face is attached to the inner facé of the 
scale. 
This is not the place for a discussion of the homologies of 
the so-called placental cushion, and I shall confine myself to the 
expression of my belief that it is a new formation for the pur- 
pose of closing the opening between the scales for the protec- 
tion of the ovules, and is not derived either from fused leaves or 
from a second integument of the ovule. 
At the time of pollination the tip of the integument is com- 
posed of about three layers of cells, but immediately after pol- 
