Biol. [f. BLASTO- + Gr. δέρμα, δέρματ. skin.] The germinal skin or membrane surrounding the yolk in the impregnated living ovum, and constituting the superficial layer of the embryo in its earliest condition. It divides into two and afterwards three layers of cells (the epiblast, mesoblast, and hypoblast: cf. -BLAST), from one or other of which all the parts of the new animal are developed.
Hence Blastodermatic, Blastodermic a., of or pertaining to the blastoderm.
1859. Todd, Cycl. Anat. & Phys., V. 46/1. A layer of nucleated organised cells, named by Pander Blastoderm or germinal membrane.
1877. Huxley, Anat. Inv. Anim., ii. 110. The cells of the blastoderm give rise to the histological elements of the adult body.
1881. Mivart, Cat, 319.
1836. Todd, Cycl. Anat. & Phys., I. 786/2. The arteries begin to show themselves … in the substance of this same blastodermic lamina. Ibid., IV. 975/1. In one germinal membrane or blastodermatic vesicle.
1877. Huxley, Anat. Inv. Anim., iv. 200. The homologue of the blastodermic disk or vesicle.
