An illusion just as great, leading to action equally violent, but ludicrous rather than painful to witness, may be seen in dogs, when encouraged by a man to the attack, and made by his cries and gestures to expect that some animal they are accustomed to hunt is about to be unearthed or overtaken; and if, when they are in this disposition, he cunningly exhibits and sets them on a dummy, made perhaps of old rags and leather and stuffed with straw, they will seize, worry, and tear it to pieces with the greatest fury, and without the faintest suspicion of its true character. That wild elephants will attack a distressed fellow seemed astonishing to Darwin, when he remembered the case of an elephant after escaping from a pit helping its fellow to escape also. But it is precisely the animals, high or low in the organic scale, that are social, and possess the instinct of helping each other, that will on occasions attack a fellow in misfortune--such an attack being no more than a blunder of the helping instinct. Felix de Azara records a rather cruel experiment on the temper of some tame rats confined in a cage. The person who kept them caught the tail of one of the animals and began sharply pinching it, keeping his hand concealed under the cage. Its cries of pain and struggles to free itself greatly excited the other rats; and after rushing wildly round for some moments they flew at their distressed companion, and fixing their teeth in its throat quickly dispatched it. In this case if the hand that held the tail had been visible and in the cage, the bites would undoubtedly have been inflicted on it; but no enemy was visible; yet the fury and impulse to attack an enemy was present in the animals. In such circumstances, the excitement must be discharged--the instinct obeyed, and in the absence of any other object of attack the illusion is produced and it discharges itself on the struggling companion. It is sometimes seen in dogs, when three or four or five are near together, that if one suddenly utters a howl or cry of pain, when no man is near it and no cause apparent, the others run to it, and seeing nothing, turn round and attack each other. Here the exciting cause--the cry for help--is not strong enough to produce the illusion which is sometimes fatal to the suffering member; but each dog mistakingly thinks that the others, or one of the others, inflicted the injury, and his impulse is to take the part of the injured animal. If the cry for help--caused perhaps by a sudden cramp or the prick of a thorn--is not very sharp or intense, the other dogs will not attack, but merely look and growl at each other in a suspicious way.