Blastosphere \Blas"to*sphere\, n. [Gr. blasto`s sprout + E.
sphere.] (Biol.)
The hollow globe or sphere formed by the arrangement of the
blastomeres on the periphery of an impregnated ovum.
Note: [See Illust. of {Invagination}.]
blastosphere
n : the blastula of mammals [syn: {blastocyst}]