The quadruped not having hands to ward off some dangers which threaten him, and to which the eyes are particularly exposed, nature has given him a movable membrane, situated within the inner corner of the eye, and which can be protruded at his pleasure, either as a defence to the eye, or to wipe off any temporary nuisance. It is sometimes called, on account of its function, the third eyelid.

The dog is more adroit in the use of his paws than many other animals are, and therefore this membrane is very little developed compared with the haw or mem-brana nictitans of the horse or ox. It is, however, far more subject to disease than the same membrane in either of those animals. A little dust or gravel sometimes insinuates itself within the folds of the membrane, and produces much inflammation and enlargement; or inflammation and enlargement arise from some unknown cause. The membrane projects at the inner corner of the eye so often as to prevent the lids from closing, while it becomes a source of very great annoyance to the poor animal. This sometimes occurs in common. inflammation of the eye, and more particularly in the., inflammation of distemper.

When the haw protrudes considerably from the corner. of the eye, warm fomentations should be first applied, consisting of simple water or a decoction of poppyheads. If no diminution of size is thus obtained, cold applications, such as water, or a very weak solution of the extract of lead in water (in the proportion of a drachm to a pint), should follow; after which light scarifications with a very fine and sharp lancet should be tried; or, last of all, a small crooked needle, armed with fine silk, should be passed through the enlarged part, and by means of which the tumour may be drawn out sufficiently far to be neatly dissected out with a pair of scissors. Very little bleeding will follow, nor will there be afterwards any apparent inconvenience to the animal and probably no very serious one.