In the lower third, however, the flap method, though exceedingly easy, and capable of very rapid performance, has certain defects; the chief of these being the tendency which the muscular flaps (the necessary result of transfixion) have to cause undue retraction, and hence protrusion of the bone. This is seen specially in the hamstrings, which from the great distance of their origin, and the purely longitudinal direction of their fibres, retract to a very great extent, much more than the anterior muscles can do from the pennate direction of their fibres, and the manner in which they are mutually bound down to each other and to the bone. Even in this one position, the lower third of the thigh, the methods that may be needed are various, and require separate notice;--for operations here are extremely frequent from the frequency of strumous disease of the knee-joint in our variable climate, and from the fact that compound fractures or dislocations of the knee-joint so very often necessitate amputation. In cases where the skin over the patella is uninjured and available, the operation by long anterior flap (either by Teale's method, or by Mr. Spence's modification of it, which curiously is almost exactly similar to the amputation of Benjamin Bell by a single flap) is suitable enough. But, I believe, preferable to either of these is the operation of Mr. Carden, already described. In cases where the knee-joint is injured, and the skin over the patella unavailable, and yet where it is not necessary to go higher up the limb, the modified circular amputation of Mr. Syme will be found very suitable. As it is in this lower third of the thigh that a very large proportion of the cases requiring a long anterior flap is to be found, it affords the best opportunity for comparing in their detail the three almost similar plans of B. Bell, Teale, and Spence--after which Mr. Syme's modified circular may be described.