Hudson has recorded[33] a number of cases of this death-feigning instinct in higher animals, and attributes it to violent emotion, or fear, that produces a sort of swoon. He describes the gaucho boys’ method, in La Plata, of catching the silver-bill by throwing a stick or a stone at it, and then rushing toward the bird, “when it sits perfectly still, disabled by fear, and allows itself to be taken.” He also states that one of the foxes (_Canis azaræ_) and one of the opossums (_Didelphys azaræ_) “are strangely subject to the death-simulating swoon.” Footnote 33: “The Naturalist in La Plata.” Hudson remarks that it seems strange that animals so well prepared to defend themselves should possess this “safeguard.” When caught or run down by dogs, the fox fights savagely at first, but after a time its efforts stop, it relaxes, and it drops to the ground. The animal appears dead, and Hudson states that the dogs are “constantly taken in by it.” He has seen the gauchos try the most barbarous tricks on a captive fox in this condition, and, despite the mutilations to which it was subjected, it did not wince. If, however, the observer draws a little away from the animal, “a slight opening of the eye may be detected, and finally, when left to himself, he does not recover and start up like an animal that has been stunned, but cautiously raises his head at first and only gets up when his foes are at a safe distance.” Hudson, coming once suddenly upon a young fox, saw it swoon at his approach, and although it was lashed with a whip it did not move. The common partridge of the pampas of La Plata (_Hothura maculosa_) shows this death-feigning instinct in a very marked degree. “When captured, after a few violent struggles to escape, it drops its head, gasps two or three times, and to all appearance dies.” But if it is released it is off in an instant. The animal is excessively timid, and if frightened, may actually die simply from terror. If they are chased, and can find no thicket or burrow into which to escape, “they actually drop down dead on the plain. Probably when they feign death in their captor’s hand they are in reality very near to death.”