_False traumatic aneurism or arterial haematoma._--This condition was met with comparatively frequently, and bears a very close relation to that already described under the heading of interstitial haemorrhages. The latter might almost have been included here, since the difference between the two conditions depended merely on the size of the vessels implicated. The exact correspondence in the period of development of some of the arterial haematomata, and of the occurrence of the aseptic form of secondary haemorrhage, also explains the pathology of the two conditions as identical; except that in the former the effused blood is retained in the tissues, while in the latter it escapes externally. The history of these cases was uniform and characteristic. A wound of the soft parts, or sometimes a fracture, was accompanied by a certain degree of primary interstitial haemorrhage, which might or might not have been associated with external bleeding. A haematoma resulted in connection with the wounded vessel, the general tendency in the effusion being to coagulation at the margins and subsequent contraction. Meanwhile the opening in the artery became more or less securely closed by the development of thrombus, and possibly by retraction of the inner and middle coats of the vessel. With the return of full circulatory force as shock passed off, or with the resumption of activity and consequent freer movement of the limb, the temporary thrombus became washed away. The newly formed wall of soft clot bounding the effusion proved insufficient to withstand the full force of the blood pressure, and extension of the cavity resulted. In the more rapidly developing haematomata, temporary pressure by the effused blood on the bleeding vessels was also, no doubt, a common explanation of temporary cessation of increase in size. A diffuse soft fluctuating swelling, sometimes accompanied by pulsation, but oftener without, developed, and not uncommonly diffusion was accompanied by some discoloration of the surface and elevation of the general temperature. Such arterial haematomata commonly developed from ten days to three weeks after the original wound. A few examples will suffice. (1) A patient wounded at Elandslaagte was sent down to Wynberg. The antero-posterior wound in the upper third of the arm was healed, but a month after the injury a large fluctuating arterial haematoma developed in the axilla and upper third of the arm. This was incised (Colonel Stevenson) and a wound of the axillary artery in its third part discovered, and the vessel ligatured. The patient made an excellent recovery.