Toe-clipping has been widely employed in field studies for marking frogs and mammals so that they can be individually recognized. This method has also been applied to salamanders with varying degrees of success but usually is unsatisfactory for long term studies because of the tendency of the animals to regenerate lost toes. Thornton (1949) found that beryllium nitrate inhibits the regeneration of limbs in larval Ambystoma which suggests that this chemical might be used for preventing regeneration of amputated toes in adult salamanders, thereby enhancing the usefulness of the toe-clipping method. The following experiment was conducted to test the feasibility of such a procedure.