Albucasis and Haly Abbas evidently copy from our author. Avenzoar prefers reducing the fleshy tumour with septics. Rhases mentions that some recommend septics in cases of encanthis, but he prefers excision. After the operation he recommends squama æris to the part. (Cont. ii.) Jesu Hali directs us to remove it with septics. (ii, 33.) It will be remarked that our author’s operation is the same as that recommended by modern authorities. SECT. XVIII.—ON PTERYGIA. This disease is occasioned by a nervous (tendinous) membrane beginning for the most part at the great canthus, and gradually spreading inwards. It proves injurious to the eye both by obstructing the motion of the ball, owing to the contractions it produces, and because when it advances forwards it covers the pupil. Those therefore which are thin and of a white colour being easiest to cure, we operate upon in this manner: having separated the eyelids, and seized upon the pterygia with a hook-like instrument, having a small curvature, we stretch it, and taking a needle having a horse-hair and a strong flaxen thread in its ear (eye?), and a little bent at the extremity, we transfix it through the middle of the pterygium, and with the thread we bind the pterygium and raise it upwards, while with the hair we separate and saw as it were the part at the pupil away unto its extremity; but the remainder of it at the great canthus we cut off from the base with the scalpel used for the operation by suture, but leaving the natural flesh of the canthus, lest there be a running of the eye when it is taken away. Some stretching as aforesaid with a thread, dissect away the whole pterygium with the instrument called pterygotomos, taking care not to touch the cornea. After the operation, having applied some levigated salts to the part, we bind on it some wool dipped in an egg. After the removal of this we inject into the eye salt water for a long time. But if inflammation supervene we have recourse to the remedies described for it. * * * * * COMMENTARY. Celsus gives an excellent account of the pterygium. He correctly states that the membrane generally begins at the inner angle of the eye. His description of the operation is very precise. The patient being properly seated, the surgeon is to raise the membrane with a sharp hook somewhat bent at the extremity, and is then to pass below it a needle armed with a thread, the two ends of which he is to lay hold of and separate the membranes everywhere from the ball of the eye. The membrane is then to be cut out with a scalpel, care being taken not to hurt the angle of the eye-lid. He directs us to apply to the part a piece of sponge, or some wool, or a pledget spread with honey. (vii, 7.)