: 
P 
STRUCTURE OF THE EMBRYO-SAC 165 
EXPLANATION OF PLATE I. 
All of the figures were drawn with a Zeiss camera — fizgs. 1, 5, Leitz; 
obj. 3, 0c. 3; figs. 9, 10,75, Leitz obj. 13, oc. 1; the other figures, Leitz obj. 
7,0. 1. Figs. 1-3, 5-9, refer to Sparganium simplex : jig. 4, to S. Greenii; 
Sigs. 10-17, to Lysichiton Kamtschatcense » fig. 18, to Anthurium cordifolium 
Kth. . 
Fic. 1. Section through the mature ovule of Sparganium Simplex , in', 
in*, the integuments ; ma, the embryo-sac. 
Fig. 2, Upper part of the nucellus and embryo-sac, showing the egg- 
apparatus; 0, the egg; s, one of the synergide. 
Fic. 3. Basal part of the embryo-sac shown in fig. 2, ant, antipodal cells; 
en, endosperm nucleus. 
Fig. 4. Antipodal cells of S. Greenit, 
Fie. 5. Longitudinal section of a recently fertilized ovule; the section 
cut at right angles to the one in Jig. I, so that the funiculus, fv, is shown. 
Fi. 6. U 
. 
pper part of embryo-sac, with one-celled embryo, em, and one 
of the secondary endosperm-nuclei, en. 
ag 7. Antipodal region of the same embryo-sac showing two of the 
‘niarged antipodals and two endosperm-nuclei, ev. 
Fic, 8. Antipodal region of an older embryo-sac, showing the large mass 
antipodal cells, and the thin parietal layer of protoplasm with the included 
endosperm nuclei, 
‘ F 'G. 9. Longitudinal section of an older ovule, showing the embryo-sac 
ined with a la. 
embryo, em. yer of endosperm, in the upper part of whichis embedded the - 
F Ace ee 
10.39. Longitudinal section of 
a young ovule of Lysichiton. 
Fic. 11, 
The nucellus of the same more highly magnified. The egg, 9, 
he synergide, s, show at the apex, and two antipodals at the base 
0-sac, 
Fig, 12 . i 
Cell only «. Longitudinal section of a nearly mature nucellus; one antipodal 
1G. 13, ; ; f 
Ag. 12, 3 The two other antipodal cells from the embryo-sac shown in 
Fr 
ms 1G, 14. Two Sections 
ton; in g the 
Fig, 15. Lon 
through the apex of a mature embryo-sac of Lysi- 
“88 and one Synergid show, the second synergid shown in 4. 
Situdinal section of an older ovule with the embryo, em, sur- 
