Next to horseflesh, sheep is preferred, and where the puma can come at a flock, he will not trouble himself to attack horned cattle. In Patagonia especially I found this to be the case. I resided for some time at an estancia close to the town of El Carmen, on the Rio Negro, which during my stay was infested by a very bold and cunning puma. To protect the sheep from his attacks an enclosure was made of upright willow-poles fifteen feet long, while the gate, by which he would have to enter, was close to the house and nearly six feet high. In spite of the difficulties thus put in the way, and of the presence of several large dogs, also of the watch we kept in the hope of shooting him, every cloudy night he came, and after killing one or more sheep got safely away. One dark night he killed four sheep; I detected him in the act, and going up to the gate, was trying to make out his invisible form in the gloom as he flitted about knocking the sheep over, when suddenly he leaped clear over my head and made his escape, the bullets I sent after him in the dark failing to hit him. Yet at this place twelve or fourteen calves, belonging to the milch cows, were every night shut into a small brushwood pen, at a distance from the house where the enemy could easily have destroyed every one of them. When I expressed surprise at this arrangement, the owner said that the puma was not fond of calves' flesh, and came only for the sheep. Frequently after his nocturnal visits we found, by tracing his footprints in the loose sand, that he had actually used the calves' pen as a place of concealment while waiting to make his attack on the sheep. The puma often kills full-grown cows and horses, but exhibits a still greater daring when attacking the jaguar, the largest of American carnivores, although, compared with its swift, agile enemy, as heavy as a rhinoceros. Azara states that it is generally believed in La Plata and Paraguay that the puma attacks and conquers the jaguar; but he did not credit what he heard, which was not strange, since he had already set the puma down as a cowardly animal, because it does not attempt to harm man or child. Nevertheless, it is well known that where the two species inhabit the same district they are at enmity, the puma being the persistent persecutor of the jaguar, following and harassing it as a tyrant-bird harasses an eagle or hawk, moving about it with such rapidity as to confuse it, and, when an opportunity occurs, springing upon its back and inflicting terrible wounds with teeth and claws. Jaguars with scarred backs are frequently killed, and others, not long escaped from their tormentors, have been found so greatly lacerated that they were easily overcome by the hunters.