Definify.com
Webster 1913 Edition
Blastosphere
Blas′to-sphere
,Noun.
[Gr.
βλαστόσ
sprout + E. sphere
.] (Biol.)
The hollow globe or sphere formed by the arrangement of the blastomeres on the periphery of an impregnated ovum.
[See Illust. of
Invagination
.]