No creature that is not capable of being bored can be capable of laughing at its own incongruous circumstances. The more simply constructed the brain and nervous system are, the less liability is there to that misfortune of ennui. We cannot imagine that a turtle's head gets tired of lying around, decapitated, for a week or more; or that a toad imprisoned in a rock or tree for one or two thousand years should become jaded by its close confinement. When the miner's pick releases him, his hop is as alert, and his appetite for the next fly as keen, as before his prison stole upon him. The lower animals are as contented as the forests and waters in which they pass an instinctive existence. Continually cheerful we may suppose they are, even when the larder is empty and the springs run low. Their monotonous round of hungering, feeding, and procreating sympathizes with the reposeful temper in which the whole of the inanimate nature discharges those functions, as we see the flower absorb, fructify, and exhale. But as the brain becomes more complicated, and capable of breeding more positive ideas and feelings,—such as the questing of a greyhound, the tact of setters and retrievers, the attachment of dogs for persons,—we may expect to observe a liability to suffer tedium. How plainly a good dog can show his disappointment when he goes out with a green sportsman, or with one who is so abstracted in his mood that he neglects the chances to shoot! The dog's natural language is that he will not tolerate such an irreligious abuse of providence: he will soon begin to sulk and not put up any more game.
