Regeneration fo the completely excised gastrocnemius muscle in the frog and rat from minced muscle fragments

In 85 frogs and 29 rats, the entire gastrocnemius muscle was removed. After removal of as much connective tissue as possible, about two-thirds of the remaining muscle was finely minced with a scissors. These minced fragments were orthotopically re-implanted, and the overlying skin was sutured. As the implanted muscle fragments degenerate, new muscle fibers appears in the regenerate. The proportion of connective tissue to muscle is usually greater than normal especially in the frog. Grossly, normal relationships are established with the cut ends of the Achilles and proximal tendons, as well as with the blood vessels and nerves. The total diameter of the regenerated muscle is almost always less than half of that seen in normal muscles. Regeneration of muscle is much more extensive in the rat than in the frog, and it occurs almost twice as rapidly. The histology of the regenerative process is described for both the frog and the rat.