2 12 
The Ohio Naturalist. 
[Vol. VIII, No. 2, 
✓ 
hypodermal, were of April 14 (Fig. 3). No integuments have 
as yet appeared. From this time on development and differen¬ 
tiation is rapid. Fig. 4 (April 21) shows the archesporial cell 
divided into parietal cell and megasporocyte. The parietal cell 
has divided into two by a vertical wall, and the incipient integu¬ 
ments are now visible as may be seen in Fig. 5. This figure also 
sho vs a further division of the parietal layer. By April 28 (Fig. 6) 
the megasporocyte has divided into four degaspores which art- 
arranged in a row, the three upper of which at once begin dis¬ 
solving. An extensive parietal tissue is formed by this time 
(Fig. 7). In Figs. 7 and 8 the outer megaspore is divided by a 
vertical wall, while in Fig. 6, the division is horizontal. This 
latter condition was the more commonly observed. The ar¬ 
rangement of the megaspores in a more or less perfect tetrad 
indicates a rather primitive position of the plant under considera¬ 
tion. The same condition was noted by Surface 1 for Sanguinaria 
canadensis and by Shreve 2 for Sarracenia purpurea. 
Embryo sac. The functional megaspore divides about 
April 28, forming the two-celled embryo sa> 'Fig. 9). The non¬ 
functional megaspores are gradually dissolving. This date also 
shows some ovules having embryo sacs with conjugating polar 
nuclei, the three antipodals, synergids and egg (Fig. 10). 
The synergids are arranged in such a manner that together with 
the egg they form a sort of tripod (See Figs. 10, 12 and 13). 
The embryo sac elongates very greatly during the next week or 
two (Fig. 11) and the antipodals come to lie close together in the 
base of the sac and are still plainly visible in sections of May 19 
(Fig. 15), though beginning to degenerate. This evanescent 
condition of the antipodals is very different from what would be 
expected in Ranunculacae. 
The polar nuclei occupy a characteristic position but remain 
side by side for an unusually long time, apparently about three 
weeks, before conjugating (Figs. 10 and 11). The various struc¬ 
tures of the embryo sac are all clearly differentiated by staining, 
so that interpretation is not difficult. 
Together with the long period during which the polar nuclei 
remain in contact without fusion, should be noted the equally 
long time that the oospore remains undivided after the beginning 
of the endosperm formation. May 19 (Fig. 16) shows the 
oospore still undivided, but there are already formed a dozen 
or more endosperm cells. 
Endosperm and embryo. In sections of May 19 (Fig. 12) 
the first endosperm wall was observed. This wall is transverse 
and divides the sac into two equal parts. The endosperm nuclei 
1. Surface.- Frank M., ’05.—Contribution to the Life History of Sanguinaria cana¬ 
densis. Ohio Nat. 6:1, 1905. 
2. Shreve, Forrest, ’06.—The Development and Anatomy of Sarracenia purpurea. 
Bot. Gaz. 42 : 107, 1906. 
