| OCR Text |
Show 208 MR. J. B. SUTTON ON DISEASES OF [Apr. 20, suffer at some period of their life from those troublesome thickenings of the skin of the feet and toes known as corns. Structurally a corn consists of thickening of the epidermis, due to pressure of an intermittent character, often the result of badly fitting boots. In many cases a small sac containing fluid m a y be detected between the thickened epidermis and the deeper tissues ; this sac is technically termed a bursa. In others the bursa is replaced by loose connective tissue which allows the corn to glide freely over the underlying structures. W e find excellent examples of corns in the ischial callosities of the Cynomorpha and in the callous pads found on the feet of Carnivora. Fig. 1. The right funicular pouch of peritoneum of Macacus sinicus, occupied by a plug of omentuni, o ; the testis, t. Of late years the attention of surgeons has been directed to corns, in consequence of a very remarkable affection to which they are liable. Under certain abnormal conditions of the spinal cord and peripheral nerves, such as locomotor ataxy, sclerosis, and peripheral neuritis, the corns ulcerate, and at last the ulceration perforates not merely the com, but the whole thickness of the foot; hence it is now familiar as the " perforating ulcer." It was to m e a matter of no small interest to find the callous pad on the foot of a Civet Cat the seat of a perforating ulcer ; the interest was considerably heightened when, on opening the spinal |
