1 文書を見つけるための辞書。

• gastrula
• 原腸胚
• double-walled stage of the embryo resulting from invagination of the blastula; the outer layer of cells is the ectoderm and the inner layer differentiates into the mesoderm and endoderm
• 胞胚の陥入によって、胎児が二重の壁で囲まれる段階