322 Oliver . — On Sar codes sanguined , Torn. 
embryo-sac elongates. The nucleus of the embryo-sac divides 
(Fig. 30), and the daughter-nuclei travel to the two ends ; a 
large vacuole arising in the protoplasm between them (Figs. 
31 and 32). Each nucleus divides a second time (Fig. 33), 
and then once again. Two of the four nuclei, at the mi- 
cropylar end, become the nuclei of the two synergidae, a third 
that of the egg-cell (oosphere), whilst the fourth moves down- 
wards and fuses with a similar, ascending one from the lower 
group, constituting the c definitive nucleus of the embryo-sac ’ 
(Figs. 34 and 35). The three nuclei, remaining at the basal 
(chalazal) end of the embryo-sac, are the nuclei of the 
antipodal cells. They become invested with cell-membranes, 
and play no further part (Figs. 34, 35, and 38). The embryo- 
sac, as represented in Fig. 34, is ready for fertilization. The 
definitive nucleus is suspended by delicate filaments of proto- 
plasm. After fertilization, the synergidae disappear and 
divisions arise in the egg-cell. Soon, a rudimentary embryo 
is formed, consisting of a short suspensor of three cells and 
an enlarged embryonic cell, in which the formation of one or 
two anticlinal walls may be traced (Figs. 36, 37, 38, and 39). 
Simultaneously with the segmentation of the egg-cell, the 
definitive nucleus divides. Each nuclear division is accom- 
panied by the formation of a delicate transverse wall (Figs. 
36, 37, and 39). The cells so arising constitute the endosperm. 
Even in the ripe seed the endosperm is relatively scanty. The 
seeds formed are extremely numerous, small and light, a con- 
dition not infrequently met with among plants with saprophytic 
or parasitic habit. They are destitute of any wing. I was 
unable to study the later stages in the development of the 
seed, owing to lack of material sufficiently advanced, but very 
few more divisions arise either in the embryo or in the en- 
dosperm. The history of this development agrees closely 
with that given by Strasburger 1 and Koch 2 , for the allied 
Monotropa . 
In this paper I have confined myself to the description of 
1 E. Strasburger, Ueb. Befruchtung und Zelltheilung. 1878. 
2 Koch, Entwickl. d. S. in Pringsheim’s Jahrb. f. wiss. Bot. xiii. 
