When the pterygium is of considerable size, extending over the cornea, the only remedy is excision. The apex of the web is laid hold of and pulled outwards by forceps or a hook, and the whole diseased part is then carefully dissected off with scissors, the incisions commencing at the apex, and being carried on to the base. The wound gradually contracts; and though an opaque cicatrix must form on the corneal surface, the speck is of much less dimensions than the space formerly occupied by the pterygium. If the web be thin and not exceedingly vascular, it may be sufficient to make a semicircular section of it transversely, by means of a hook and scissors, between its base and the margin of the cornea; its growth is thereby arrested, and there is a probable chance of its beginning to diminish, and ultimately disappearing. When it is small, and so situated as to cause no impairment of vision, it is prudent and good practice not to interfere with it at all. DISEASES OF THE EYEBALL are numerous, and various in their nature. Some are acute, others chronic; and their attack is either sudden, or slow and insidious. Most of them are attended with pain and other annoying symptoms, and some cause loss of vision. Some are cured by internal means; others require surgical operations; and the cure is either complete and permanent, or palliative and temporary. Some destroy the organ, and others, still more malignant, cause extinction of life. All require much attention and care. _Of Ophthalmia, or Inflammation of the Eye._—The symptoms and appearances of ophthalmia vary much according to the particular texture or textures affected. They require to be minutely attended to, that the treatment may be varied in such a way as to obviate any bad consequences which may be threatened. The great importance of the organ, and the danger to its structure and functions which is likely to occur from any other termination of the affection than resolution, must never be lost sight of. We shall first treat of inflammation of the more external parts of the ball, an affection generally less dangerous than inflammation of the interior, but at the same time of more frequent occurrence, and produced by slighter causes.