The macrospore divides into two cells, a large lower one, and a smaller upper one.    From Wordnik.com.  [Elements of Structural and Systematic Botany For High Schools and Elementary College Courses] Reference

The nucellus is a cellular tissue enveloping one large cell, the embryo-sac or macrospore.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1] Reference

But the formation of the macrospore or embryo-sac is simpler than the corresponding process in cryptogams.    From Wordnik.com.  [Scientific American Supplement, No. 531, March 6, 1886] Reference

It arises by a simple enlargement of one cell of the nucleus instead of by the division of one cell into four, each thus becoming a macrospore.    From Wordnik.com.  [Scientific American Supplement, No. 531, March 6, 1886] Reference

The germination of the macrospore consists in the repeated division of its nucleus to form two groups of four, one group at each end of the embryo-sac.    From Wordnik.com.  [Encyclopaedia Britannica, 11th Edition, Volume 2, Part 1, Slice 1] Reference

In the full-grown ovule the macrospore, which in the seed plants is generally known as the "embryo sac," is completely filled with the prothallium or "endosperm.".    From Wordnik.com.  [Elements of Structural and Systematic Botany For High Schools and Elementary College Courses] Reference

When we compare the embryo sac (macrospore) of the angiosperms with that of the gymnosperms a great difference is noticed, there being much more difference than between the latter and the higher pteridophytes.    From Wordnik.com.  [Elements of Structural and Systematic Botany For High Schools and Elementary College Courses] Reference

At the top of this macrospore or embryo-sac two or three germinal vesicles are formed by free cell formation, and also two or three cells called antipodal cells, since they travel to the other end of the embryo-sac; these latter represent a rudimentary prothallium.    From Wordnik.com.  [Scientific American Supplement, No. 531, March 6, 1886] Reference

The macrospore or embryo-sac produces a prothallium called the endosperm, in which archegonia or corpuscula are formed; and lastly, in typical dicotyledons it is only lately that any trace of a prothallium from the microspore or pollen cell has been discovered, while the macrospore or embryo-sac produces only two or three prothallium cells, known as antipodal cells, and two or three oospheres, known as germinal vesicles.    From Wordnik.com.  [Scientific American Supplement, No. 531, March 6, 1886] Reference

(macrospore).    From Wordnik.com.  [Elements of Structural and Systematic Botany For High Schools and Elementary College Courses] Reference