“…There is a double response which consists of a fast initial contraction associated with a burst of fibrillary potentials followed by a slow contracture and the abolition of fibrillation (Brown, 1937;Rosenblueth & Luco, 1937;Bowman & Raper, 1964). Chronically denervated muscle has usually been reported to produce single phase contractions when isolated (Elmqvist & Thesleff, 1960;Letley, 1960;Freeman & Turner, 1969;Lullmann & Sunano, 1973), but biphasic responses have been obtained in the chronically denervated and isolated diaphragm (Preuner, 1971;Liillman, Preuner & Schaube, 1974) and soleus muscle (Hall, Maleque & Wadsworth, 1975).…”