A FEW EXPERIMENTS WITH THIERSCH'S GRAFTS IN THE OPERATION FOR PTERYGIUM.

A pterygium is nothing but a fold of ocular conjunctiva drawn over and fastened to the cornea, and to make our operation for pterygium a permanent success, we must after releasing the conjunctival fold from the cornea, arrange matters so that the conjunctiva cannot be drawn back over the cornea again. In a pterygium of moderate size this aim is usually attained by a very simple operation. The conjunctival fold is carefully dissected from the cornea, and allowed to retract as far as it will, from the corneal margin. This leaves between the retracted conjunctiva and the cornea, a small wound area to close which we draw the conjunctiva from above and below together, and unite the edges by two sutures. If this wound heals by first intention, there is no danger of a recurrence of the pterygium. But in a number of cases the pterygium is so large, and