Stories We Like: A Guide to the Comma
blastema blas·te·ma (blā-stē'mə)
The formative, undifferentiated material from which cells are formed.
A mass of embryonic cells from which an organ or a body part develops, either in normal development or in the regeneration of a lost body part.
in zoology, a mass of undifferentiated cells that has the capability to develop into an organ or an appendage. In lower vertebrates the blastema is particularly important in the regeneration of severed limbs. In the salamander, for example, tissues in the stump of a limb dedifferentiate-that is, they lose their individual characteristics-and revert to an embryonic appearance. Under the influence of regenerating nerve fibres, they will form a blastema, a mound of cells resembling the original limb bud, from which the replacement limb gradually emerges.