Play is a common habit of animals. Darwin, Wallace, and others have emphasized its importance as a progressive evolutionary factor in the survival of the fittest. Play is rest and relaxation; it gives power and proficiency; it stimulates the brain to the highest pitch of keenness and arouses all the faculties to be eager and at their best; it develops the individual. Play not only is a profound advantage to the player, but is necessary to the requirements of an efficient life. All alert animals freshen themselves with play. The human race is beginning to do intelligently what it once did instinctively; it is relearning the lost art, the triumphant habit, of play. Matching Wits with the Grizzly In April, 1904, "Old Mose," an outlaw grizzly, was killed on Black Mountain, Colorado. For thirty-five years he had kept up his cattle-killing depredations. During this time he was often seen and constantly hunted, and numerous attempts were made to trap him. His home territory was about seventy-five miles in diameter and lay across the Continental Divide. He regularly killed cattle, horses, sheep, and hogs in this territory, and, so far as known, did not leave this region even briefly. Two missing toes on his left hind foot were the means of identifying his track. Old Mose killed at least five men and eight hundred cattle, together with dozens of colts and other live stock. His damage must have exceeded thirty thousand dollars. Often he smashed the fences that were in his way. He had a fiendish habit of slipping up on campers or prospectors, then rushing into their camp with a roar, and he evidently enjoyed the stampedes thus caused. On these occasions he made no attempt to attack. Although he slaughtered stock to excess, he never went out and attacked people. The five men whom he killed were men who had cornered him and were attempting to kill him. Rarely do grizzlies kill cattle or big game. Old Mose was an exception. None of the other grizzlies in the surrounding mountains killed live stock. During his last years Old Mose was followed at a distance by a "cinnamon" bear of large size. This grizzly had nothing to do with the killing, never associated with Old Mose, but simply fed on the abundance which he left behind. A heavy price on his head led the most skillful hunters and trappers to try for Old Mose. Three of the best hunters were killed by him. All trapping schemes failed; so, too, did attempts to poison. Finally he was cornered by a pack of dogs, and the hunter ended his career with the eighth shot. Though Old Mose was forty or more years of age when killed, his teeth were sound, his fur was in good condition, and he had every appearance of being in excellent health. He was apparently good for several years more of vigorous life.