A green jay killed a blue jay. A jay-thrush and several smaller birds were killed by laughing thrushes,--which simply love to do murder! A nightingale was killed by a catbird and two mocking- birds. Two snake-birds killed a third one--all of them thoroughly depraved villains. Three gulls murdered another; a brown pelican was killed by trumpeter-swans; and a Canada goose was killed by a gull. All these victims were birds in good health. It is deplorable, but nevertheless true, that in large mixed companies of birds, say where forty or fifty live together, it is a common thing for a sick bird to be set upon and killed, unless rescued by the keepers. In crimes of this class birds often murder their own kind, but they are quite as ready to kill members of other species. In 1902 a sick brant goose was killed by its mates; and so were a red-tailed hawk, two saras cranes, two black vultures, a road-runner, and a great horned owl. An aged and sickly wood ibis was killed by a whooping crane; and a night heron killed its mate. Strange as it may seem, among reptiles there is far less of real first-degree murder than among mammals and birds. Twenty rattlesnakes may be crowded together in one cage, without a family jar. Even among cobras, perhaps the most irritable and pugnacious of all serpents, I think one snake never wantonly murders another, although about once in twenty years one will try to swallow another. The big pythons and anacondas never fight, nor try to commit murder. And yet, a twenty-foot regal python with a bad heart--like Nansen's polar bear--could easily constrict and kill any available snake of smaller size. At this moment I do not recall one instance of wanton murder among serpents. It is well known that some snakes devour other snakes; but that is not crime. The record of the crocodilians is not so clear. It is a common thing for the large alligators in our Reptile House to battle for supremacy and in these contests several fatalities have occurred. Some of these occurrences are not of the criminal sort; but when a twelve-foot alligator attacks and kills a six-foot individual, entirely out of his class and far too small to fight with him, it is murder. An alligator will seize the leg of a rival and by violently whirling around on his axis, like a revolving shaft, twist the leg completely off. Among sea creatures, the clearly defined criminal instinct, as exhibited aside from the never-ending struggle for existence and the quest of food, is rarely observed, possibly because opportunities are so few. The sanguinary exploits of the grampus, or whale-killer, among whales small enough to be killed and eaten, are the onslaughts of a marine glutton in quest of food.