Cretinism has been observed in animals. If attention were directed to this inquiry, it might be found that it is not so exceedingly rare as would be judged from the few observations that have been recorded. A cretin, if a wild animal, falls an easy prey. If a domesticated animal, little trouble is taken to insure its survival. A myxœdematous pig is a dwarf with coarse, sparse hair, thick, warty hoofs, large jowl, heavy ears. It is apathetic. A piglet presenting these characteristics is not altogether uncommon in a litter. Among chickens and pigeons, also, individuals appear which might, judging from their uncouth appearance and mental dulness, be suffering from cretinism. The only way of proving that this is the case is to feed them on thyroid glands; it does not matter from what animal the gland is obtained. Operative cretins, produced by removing the thyroid gland soon after birth, recover their natural characters on a diet containing a daily allowance of thyroid gland. The coarse hairs, or wiry towsled feathers, fall off, and are replaced by a smooth, supple growth. The thickened skin becomes soft and pliant. Mental apathy gives place to alertness. They make up for lost time by growing more rapidly than other animals of the same age, which have not been operated upon, although they never surpass the normal stature. =Suprarenal Capsules.=—Each of the kidneys is capped by a pyramidal body weighing about ⅛ ounce. Small though it be, this organ is essential to life. As Dr. Addison was the first to discover, in 1855, its disease results in a cycle of symptoms which invariably has a fatal termination. A college friend of the writer suffered from “slackness.” Before he had finished a set of tennis, he abandoned the game, and spent the rest of the afternoon lying on the grass, wrapped in a rug. After hall, although he earnestly desired to conquer the subtleties of the Greek grammar, he fell asleep over his books. As his countenance was not ruddy merely, but bronzed like that of a man who has just returned from a yachting cruise, he was the butt of many a joke. Although already a qualified medical man, who had been in practice—he had come to the University with a view to adding the degree of M.D. to his M.R.C.S.—he had no suspicion that he was ill. Thought he wanted “freshening up.” Took a trip across the Atlantic. Stumbled over a rope on landing; broke his thigh. Spent two months in a New York Hospital, but the bone did not mend. At last, the surgeons, growing anxious, sent him back to London. He was seen by a leading physician, who told him that he was suffering from Addison’s disease. Two months later he died of failure of the heart. Disease of the suprarenal capsules is usually of tuberculous origin. Its symptoms: muscular weakness and excessive liability to fatigue; abnormal pigmentation of the skin; lowered blood-pressure, and consequent sensitiveness to cold; cardiac weakness.