occasionally occurs throughout a whole litter, no doubt being entailed upon the progeny of those dogs who have defective vision, or who are old and infirm at the time of copulation. The best and only remedy is speedy drowning. CATARACT consists in the partial or complete opacity of the crystalline lens; it results from numerous causes, and is more frequent in the old than the young subject. In old dogs both eyes are usually attacked, producing absolute blindness, while in young animals one eye alone is generally attacked. 'Causes.'--Old age, hard work, and bad feeding, are the agents most active in the production of this affection; it generally comes on slowly, but sometimes very quickly. When the disease occurs in young dogs, it is generally the result of wounds or blows over the head, convulsions and falls. 'Treatment.'--Little can be accomplished towards curing this disease either in the old or young dog, as the disease, in spite of all our efforts, will run its course, and terminate in total opacity of the lens. Mild purging, blistering on the neck, introduction of the seton, and blowing slightly stimulating powders into the eye, will sometimes arrest the progress of the disease in the young dog. ULCERATIONS ON THE CORNEA are sometimes very troublesome, and if not put a stop to, will often cause opacity and blindness, if not total destruction of the eye. Slightly stimulating washes and purges are useful; the careful application of nitrate of silver will often induce the ulcer to heal; it must be put on very nicely and gently. SPOTS ON THE CORNEA are the result of ulcers and inflammation. If they do not materially interfere with vision, they had better be left alone. Powdered sugar and a small quantity of alum blown into the eye daily through a quill, we have seen used with much success. AMAUROSIS--GUTTA SERENA OR GLASS EYE, A partial or complete paralysis of the optic nerves of either side is not a frequent disease. It usually comes on gradually, but sometimes may appear in the course of a few hours from the effects of wounds or convulsions. When the paralysis is complete, total blindness of course ensues. The intimate connection, or sympathy, existing between the nerves of either eye, is so peculiar that disease of one is quickly followed by a corresponding disease in the other. Amaurosis, therefore, ordinarily ends in total blindness. The disease is characterized by a dilated stage of the pupil, which seldom contracts under the effect of any degree of light thrown upon it. The coats and humours of the eye are perfectly transparent, in fact appear to be more pellucid than natural. 'Causes.'--This affection is produced in many different ways; among the most common causes may be mentioned wounds on the head, or of the parts surrounding the nerve, strains, falls, disease of the bone, convulsions, and epileptic fits.