_F._ A slight improvement on _E_, made by Hey of Leeds, who advised that the posterior muscles of the limb should be divided at a lower level than the anterior, to compensate for their greater range of contraction. 2. In the progress of the flap operation fewer stages can be defined. Made by cutting from within outwards, after transfixion of the limb, the flaps varied in shape, size, position, and numbers, from the single posterior one of Verduyn of Amsterdam, to the two equal lateral ones of Vermale, and the equal anterior and posterior ones of the Edinburgh school. Then came the battle of the schools: flap or circular. _Flap._--Speedy, easy, and less painful; apt to retract, and that unequally. _Circular._--Leaving a smaller wound, but more slow in performance, and apt to leave a central adherent cicatrix. 3. The last era in amputation began after the introduction of anæsthetics. Now speed in amputation is no object, and the surgeon has full time to shape and carve his flaps into the curves most suited for accurate apposition, and suitable relation of the cicatrix to the bone. It has also been brought clearly out that different methods of operating are suitable for different positions, and also that even in the same operation it is possible to unite the advantages of both the flap and the circular method. In the modified circular, which is best suited for amputation below the knee, in the long anterior flaps of Teale, Spence, and Carden, we have illustrations of the manner in which the advantages of both the flap and circular methods have been secured, without the disadvantages of either. The long anterior flap, not like Teale's to fold upon itself, but like Spence's and Carden's to hang over and shield the end of the bones, and the face of a transversely-cut short posterior flap, seems to be now the typical method for successful amputations. There may be exceptions, as when the anterior skin is more injured than the posterior, or where an anterior flap would demand too great sacrifice of length of limb, but as a rule it will be found the best method for the patient.