Any of the blastomeres from which the ectoderm develops.
the blastomeres from which the ectoderm forms
The more clear cells, which eventually come to be additional, in lots of segmenting ova, as those of mammals.
In embryology, the less granular associated with two blastomeres into that your mammalian ovum divides: additionally placed on a descendant of the blastomere in the first stages of development. See blastomere, entomere.