There he continued his study of the embryo-sac in Orchideae, as Sachs subsequently testified, "zu meiner vollsten Zufriedenheit."
He also recognised and figured the great prolongation backwards of the embryo-sac as an empty, absorbent caecum.
And he observed the extension of the embryo-sacs up the style and the union of the pollen tube with the tip of the embryo-sac.
One of the cells of the nucleus near its apex then enlarges, so as to form a sac, called the embryo-sac.
The nucellus is a cellular tissue enveloping one large cell, the embryo-sac or macrospore.
But the formation of the macrospore or embryo-sac is simpler than the corresponding process in cryptogams.
embryo sac |
An oval structure within an ovule of an angiosperm that contains the egg. Together with the fertilized egg, it develops into a seed. The embryo sac is the female gametophyte of angiosperms, consisting of eight nuclei: the egg and two adjacent and short-lived synergids that are near the micropyle (the opening where the pollen nuclei will enter), two central nuclei (which will combine with one of the pollen nuclei to form the endosperm), and three antipodal nuclei at the end of the embryo sac opposite the micropyle. Like the synergids, these nuclei degenerate at or shortly after fertilization. See more at gametophyte, pollination.