The puma is, with the exception of some monkeys, the most playful animal in existence. The young of all the Felidae spend a large portion of their time in characteristic gambols; the adults, however, acquire a grave and dignified demeanour, only the female playing on occasions with her offspring; but this she always does with a certain formality of manner, as if the relaxation were indulged in not spontaneously, but for the sake of the young and as being a necessary part of their education. Some writer has described the lion's assumption of gaiety as more grim than its most serious moods. The puma at heart is always a kitten, taking unmeasured delight in its frolics, and when, as often happens, one lives alone in the desert, it will amuse itself by the hour fighting mock battles or playing at hide-and-seek with imaginary companions, and lying in wait and putting all its wonderful strategy in practice to capture a passing butterfly. Azara kept a young male for four months, which spent its whole time playing with the slaves. This animal, he says, would not refuse any food offered to it; but when not hungry it would bury the meat in the sand, and when inclined to eat dig it up, and, taking it to the water-trough, wash it clean. I have only known one puma kept as a pet, and this animal, in seven or eight years had never shown a trace of ill-temper. When approached, he would lie down, purring loudly, and twist himself about a person's legs, begging to be caressed. A string or handkerchief drawn about was sufficient to keep him in a happy state of excitement for an hour; and when one person was tired of playing with him he was ready for a game with the next comer. I was told by a person who had spent most of his life on the pampas that on one occasion, when travelling in the neighbourhood of Cape Corrientes, his horse died under him, and he was compelled to continue his journey on foot, burdened with his heavy native horse-gear. At night he made his bed under the shelter of a rock, on the slope of a stony sierra; a bright moon was shining, and about nine o'clock in the evening four pumas appeared, two adults with their two half-grown young. Not feeling the least alarm at their presence, he did not stir; and after a while they began to gambol together close to him, concealing themselves from each other among the rocks, just as kittens do, and frequently while pursuing one another leaping over him. He continued watching them until past midnight, then fell asleep, and did not wake until morning, when they had left him.