Molina, in his _Natural History of Chill,_ says the vizcacha uses its tail as a weapon; but then Molina is not always reliable. I have observed vizcachas all my life, and never detected them making use of any weapon except their chisel teeth. The tail is certainly very curious, being straight at the base, then curving up outwardly, and slightly down again at the tip, resembling the spout of a china teapot. The under surface of the straight portion of the base is padded with a thick, naked, corneous skin; and, when the animal performs the curious sportive antics in which it occasionally indulges, it gives rapid loud-sounding blows on the ground with this part of the tail. The peculiar form of the tail also makes it a capital support, enabling the vizcacha to sit erect, with ease and security. The frog is a most timid, inoffensive creature, saving itself, when pursued, by a series of saltatory feats unparalleled amongst vertebrates. Consequently, when I find a frog, I have no hesitation in placing my hands upon it, and the cold sensation it gives one is the worse result I fear. It came to pass, however, that I once encountered a frog that was not like other frogs, for it possessed an instinct and weapons of offence which greatly astonished me. I was out snipe shooting one day when, peering into an old disused burrow, two or three feet deep, I perceived a burly-looking frog sitting it. It was larger and stouter-looking than our common Rana, though like it in colour, and I at once dropped on to my knees and set about its capture. Though it watched me attentively, the frog remained perfectly motionless, and this greatly surprised me. Before I was sufficiently near to make a grab, it sprang straight at my hand, and, catching two of my fingers round with its fore legs, administered a hug so sudden and violent as to cause an acute sensation of pain; then, at the very instant I experienced this feeling, which made me start back quickly, it released its hold and bounded out and away. I flew after it, and barely managed to overtake it before it could gain the water. Holding it firmly pressed behind the shoulders, it was powerless to attack me, and I then noticed the enormous development of the muscles of the fore legs, usually small in frogs, bulging out in this individual, like a second pair of thighs, and giving-it a strangely bold and formidable appearance. On holding my gun within its reach, it clasped the barrel with such energy as to bruise the skin of its breast and legs. After allowing it to partially exhaust itself in these fruitless huggings, I experimented by letting it seize my hand again, and I noticed that invariably after each squeeze it made a quick, violent attempt to free itself. Believing that I had discovered a frog differing in structure from all known species, and possessing a strange unique instinct of self-preservation, I carried my captive home, intending to show it to Dr. Burmeister, the director of the National