[Footnote 1: The sheath of the canal, together with the crural septum, constitutes the "fascia propria" of the hernia (Sir Astley Cooper). Mr. Lawrence denies the existence of the crural septum.] [Footnote 2: The "upper cornu of the saphenous opening," the "falciform process" (Burns), and the "femoral ligament" (Hey), are names applied to the same part. With what difficulty and perplexity does this impenetrable fog of surgical nomenclature beset the progress of the learner!] [Footnote 3: The neck of the sac at the femoral ring lies very deep, in the undissected state of the parts (Lawrence).] The crural hernia is much more liable to suffer constriction than the inguinal hernia. The peculiar sinuous course which the former takes from its point of origin, at the crural ring, to its place on Poupart's ligament, and the unyielding fibrous structures which form the canal through which it passes, fully account for the more frequent occurrence of this casualty. The neck of the sac may, indeed, be supposed always to suffer more or less constriction at the crural ring. The part which occupies the canal is also very much compressed; and again, where the hernia turns over the falciform process, this structure likewise must cause considerable compression on the bowel in the sac. [Footnote] This hernia suffers stricture of the passive kind always; for the dense fibrous bands in its neighbourhood compress it rather by withstanding the force of the herniary mass than by reacting upon it. There are no muscular fibres crossing the course of this hernia; neither are the parts which constrict it likely to change their original position, however long it may exist. In the inguinal hernia, the weight of the mass may in process of time widen the canal by gravitating; but the crural hernia, resting on the pubic bone, cannot be supposed to dilate the crural ring, however greatly the protrusion may increase in size and weight. [Footnote: Sir A. Cooper (Crural Hernia) is of opinion that the stricture is generally in the neck of the sheath. Mr. Lawrence remarks, "My own observations of the subject have led me to refer the cause of stricture to the thin posterior border (Gimbernat's ligament) of the crural arch, at the part where it is connected to the falciform process." (Op. cit.) This statement agrees also with the experience of Hey, (Practical Obs.)] DESCRIPTION OF THE FIGURES OF PLATES 43 & 44. PLATE 43. FIGURE 1. A. Anterior superior iliac spine. B. Iliacus muscle, cut. C. Anterior crural nerve, cut. D. Psoas muscle, cut. E. Femoral artery enclosed in e, its compartment of the femoral sheath. F. Femoral vein in its compartment, f, of the femoral sheath. G. The fascia propria of the hernia; g, the contained sac. H. Gimbernat's ligament. I. Round ligament of the uterus. [Illustration: Abdomen, showing bone, blood vessels and other internal organs.] PLATE 43.--FIGURE 1. FIGURE 2. A. Anterior superior iliac spine. B. Symphysis pubis.