The sense of humor must surely exist in individual dogs; otherwise it would puzzle me to account for the singular practical jokes played off by a water-spaniel once possessed by me. This individual, whose name was Muff, was a rather small-sized one, of the pure Kentish blood; liver-colored, with a white ring on his neck, and white paws; close-curled, wicked-eyed, deep-chested, and remarkably powerful for his size. Professionally a retriever,--and one of great promise, although never fully tested with the gun,--his leisure hours, which included every one in the twenty-four, were passed in the invention and perpetration of curiously regulated mischiefs, with all of which he took pains to combine an element of the ludicrous. His great spree was to run amuck into a flock of small children coming out of school. If there was a dirty crossing hard by, over which they had to pass, he would wait until they had got half-way, and then, going through them like a rocket, would chuck them down into the mud, right and left, as he sped, keeping straight on in his career until far beyond range of pedagogue's rod. His trick of making a sudden rush at the heels of unsuspecting persons--and he invariably selected the right sort for his purpose--might often have got me into ugly scrapes, but for the tact with which he invariably ignored his master on such occasions. If pursued, he never came near me for protection, but fled wildly on, assuming the character of a dog "on the loose," belonging to nobody in particular, and quite able to take care of himself. He had a decided objection to street industrials in general, including Italian organ-grinders and image-sellers. Once I saw him crouching stealthily after one of the latter, who was passing through an open square with a tray of casts upon his head; and before I could get up a whistle or call him off by name, he had darted like a javelin at the legs of the refugee, startling him so much out of the perpendicular that the superstructure of plastic art came to the ground with a crash, top-dressing the sterile soil of the Campus Martius with a coat of manufactured plaster of Paris. Marius, blubbering over the shattered chimney-stacks of Carthage, could not have displayed a more touching classical spectacle than did that modern Roman lamenting to and fro among the fragments of his collapsed martyrs and ruined saints; nor were his pangs fully assuaged even by the application of the universal panacea to an amount more than double the value of his lost wares.