I have met with some curious instances of the paralyzing effect of fear. I was told by some hunters in an outlying district of the pampas of its effect on a jaguar they startled, and which took refuge in a dense clump of dry reeds. Though they could see it, it was impossible to throw the lasso over its head, and after vainly trying to dislodge it, they at length set fire to the reeds. Still it refused to stir, but lay with head erect, fiercely glaring at them through the flames. Finally, it disappeared from sight in the black smoke; and when the fire had burned itself out, it was found, dead and charred, in the same spot. On the pampas, the Gauchos frequently take the black-necked swan by frightening it. When the birds are feeding or resting on the grass, two or three men or boys on horseback go quietly to leeward of the flock, and, when opposite to it, suddenly wheel and charge it at full speed, uttering loud shouts, by which the birds are thrown into such terror that they are incapable of flying, and are quickly despatched. I have also seen Gaucho boys catch the silver-bill (Lichenops perspicillata) by hurling a stick or stone at the bird, then rushing at it, when it sits perfectly still, disabled by fear, and allows itself to be taken. I myself once succeeded in taking a small bird of another species in the same way. Among mammals, our common fox (Canis azaræ), and one of the opossums (Didelphys azaræ), are strangely subject to the death-simulating swoon. For it does indeed seem strange that animals so powerful, fierce and able to inflict such terrible injury with their teeth should also possess this safeguard, apparently more suited to weak inactive creatures that can not resist or escape from an enemy and to animals very low down in the scale of being. When a fox is caught in a trap or run down by dogs, he fights savagely at first, but by and by relaxes his efforts, drops on the ground and apparently yields up the ghost. The deception is so well carried out that dogs are constantly taken in by it, and no one, not well acquainted with this clever trickery of nature, but would at once pronounce the creature dead, and worthy of some praise for having perished in so brave a spirit.