1918] OTTLEY—IMPATIENS 295 
vacuole; while PACE (36) finds the synergid vacuoles of Parnassia 
in various positions. 
The antipodals are surrounded by denser cytoplasm than is 
present above them, and they appear rarely as separate cells with 
delicate walls separating them (fig. 18), or, as is more commonly 
found, the mass of cytoplasm with the 3 nuclei is more or less 
cut off from the rest of the sac by a membrane but the cells are 
not separated. In either case they are but short-lived and dis- 
appear soon after the egg apparatus is formed. The embryo sac 
then persists for a long time with but 5 nuclei. Miss Rarrr says 
that the antipodals in J. pallida cannot be distinguished with 
certainty and are evidently transitory. This ephemeral nature 
of the antipodals is common among many of the angiosperms. In 
Striga lutea (MICHELL 29) the 3 antipodal cells begin to disintegrate 
before fertilization. In Richardia africana (MICHELL 30) the 
disintegration is somewhat earlier, evidently more nearly like 
I. Sultani. In this species the antipedals were never found to 
increase in size or number and grow into the adjoining tissue, as 
has been described by CHAMBERLAIN (12) and OpPERMAN (34) for 
Aster novae-angliae and by others for various plants. 
Very quickly after the 8 nuclei of the sac have been formed 
the antipodal polar moves up toward the micropylar polar and the 
2 nuclei remain near each other at a short distance below the egg 
nucleus for some time. The nuclei may or may not be spherical, 
but they always contain a prominent nucleolus with a small highly 
refractive spot at the center. The chromatic substance of the 
polar nuclei is small in amount and forms either a delicate network 
lying just within the nuclear membrane, or a few strands radiating 
out from the nucleolus. Most of the food stored in the sac at an 
earlier period disappears before the female gametophyte reaches 
maturity and the sac becomes very vacuolate, with only a layer of 
cytoplasm at its periphery and surrounding the nuclei in the 
micropylar half of the sac (fig. 37). 
During the later development of the embryo sac its shape 
becomes much changed (figs. 17, 19, 37). While the antipodals 
are still present the sac is a little over three times longer than wide, 
with the micropylar and antipodal ends both rounded in outline 
