A blastoderm is a germination point in an ovum from which the embryo develops.

a blastoderm

Wharton B. Mather has written:

'A third race of Drosophila rubida' -- subject(s): Diptera, Drosophila

'The technique of rabbit blastoderm culture' -- subject(s): Rabbits, Blastoderm

bipedalism, blastoderm, bolshevism, boosterism, bourbonism, brainstorm, bridegroom

The blastodisc is used to keep the girl part of the yolk still while the male part disconnects to mate with the female