[Organization and differentiation of the somite mesoderm cultured in the presence of adjacent tissues (notocord, spinal cord, ectoderm, endoderm) in anurans].

The explantation of pieces of somitic mesoderm alone or in association with neighbouring tissues (notochord, spinal cord, ectoderm, endoderm) shows slearly the power of self-differentiation of the somitic tissue. Only, the spinal cord does not stimulate the differentiation of the somitic mesoderm into muscular tissue. Only the notochord does not stimulate the formation of typical myotomes. It seems that ii does not possess biochemical activity, its effect if reduced to a mechanical role.