478 
The Ohio Naturalist. 
[Vol. IX, No. 6, 
The most striking characters noted in the study of the 
Agrostemma githago referred to above were (a) the formation 
of an inner and an outer nucellar zone, (b) the growth of the 
nucellus so as to leave the embryo sac deeply embedded, (c) the 
formation of a nucellar beak which projects through the micro- 
pyle, and (d) a filamentous embryo with the large basal cell. 
Since the publication of the above paper, L. S. Gibbs has pub¬ 
lished a paper on “Notes on the Development and Structure of 
the Seed in Alisnoideae”! in which the characters were very 
similar to A. githago. The development of the embryo sac was 
the same, also the two zones, which are referred to as nucellar 
layers, and the beak like projection of the nucellus through the 
micropyle which is somewhat more pointed than in A. githago 
and is referred to as a papilla. There is no lateral pouch-like 
enlargement of the sac as in A. githago. The development of 
the embryo is practically the same. 
No attempt was made to trace the early history of the embryo 
sacs in either species. In both species the two nucellar zones 
and the beak were very evident; the sacs are located deep in the 
nucellus but there was no pronounced lateral enlargement as in 
the case of A. githago although in some instances there was a 
slight enlargement of this kind. In both species the embryos 
were filamentous in their early stages and possess the large 
basal cells. 
In V. vaccaria the embryo was exceptionally long (Fig. 1), 
the length being due to the excessive length of the three lower 
cells. The basal cell becomes very large, stains readily and has 
very much the appearance of the corresponding cell in A. githago. 
It is also directly connected with the passage through which the 
pollen tube entered and which is now filled with protoplasm. 
Gibbs savs that in Stellaria this basal cell is “elongated so much 
that it forms a haustorium at the micropolar end, which projects 
beyond the embryo sac into the nucellar tissue.’’ Gibbs also 
says that “the nucellus is very large and active in appearance, 
and the cell suggests an absorbent organ.’’ 
In Silene conoidea the embryo is not so long as in V. vaccaria 
but is almost identical in development with A. githago (Fig. 3). 
However, instead of the cell next to the apical cell being the first 
to divide, it is usually the second from the apical cell (Fig. 4). 
The large basal cell eventually disentegrates (Fig. 5) and the 
further history of the embryo is practically the same as in A. 
githago. In one instance an abnormal embryo (Fig. (i) was 
observed. 
The endosperm in both species was non-cellular (Fig. 3) and 
identical with the endosperm in A. githago. 
t Annals of Botany, Vol. XXI, pp. 2f>-55, 1907. 
