Origin of embryo sac
Examples from the Web for embryo sac
One of the cells of the nucleus near its apex then enlarges, so as to form a sac, called the embryo-sac.An Elementary Text-book of the Microscope|John William Griffith
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.
But the formation of the macrospore or embryo-sac is simpler than the corresponding process in cryptogams.
He also recognised and figured the great prolongation backwards of the embryo-sac as an empty, absorbent caecum.
The nucellus is a cellular tissue enveloping one large cell, the embryo-sac or macrospore.