The development of the skeletal muscular tissue from the frog Rana ridibunda was studied under autotransplantation and cultivation in diffusion chambers of the minced gastrocnemius muscle implanted intraperitoneally to other species of the same family. The material was examined by light or scanning electron microscopy. In both series of experiments, the muscular tissue from adult frogs retained its viability and reconstructive activity for a long time. The muscle material underwent reconstruction starting from myoblast formation by means of their separation and migration from disintegrating muscle fibers. The reconstruction eventuated in the formation of differentiated muscle fibers. The development of the muscular tissue proceeded more rapidly during cultivation in diffusion chambers under homo-implantation as compared with the process occurring in the minced muscle autotransplant.