Yet the analogy only half holds. Memories of the most tenacious kind the animals surely have; but little or no voluntary, unaided power to use them. Memory is largely a mechanical, a crank process with the animals, a kind of magic-lantern show, where the concrete slide is necessary for the picture on the screen; else the past as the future hangs a blank. The dog will sometimes seem to cherish a grudge; so will the elephant. Some one injures or wrongs him, and the huge beast harbors the memory, broods it, and waits his opportunity for revenge. Yet the records of these cases usually show the creature to be living with the object of his hatred--keeper or animal--and that his memory goes no further back than the present moment, than the sight of the enemy; memory always taking an immediate, concrete shape. At my railroad station I frequently see a yoke of great sleepy, bald-faced oxen, that look as much alike as two blackbirds. Their driver knows them apart; but as they stand there bound to one another by the heavy bar across their foreheads, it would puzzle anybody else to tell Buck from Berry. But not if he approach them wearing an overcoat. At sight of me in an overcoat the off ox will snort and back and thresh about in terror, twisting the head of his yoke-fellow, nearly breaking his neck, and trampling him miserably. But the nigh ox is used to it. He chews and blinks away placidly, keeps his feet the best he can, and doesn’t try to understand at all why great-coats should so frighten his cud-chewing brother. I will drop off my coat and go up immediately to smooth the muzzles of both oxen, blinking sleepily while the lumber is being loaded on. Years ago, the driver told me, the off ox was badly frightened by a big woolly coat, the sight or smell of which suggested to the creature some natural enemy, a panther, perhaps, or a bear. The memory remained, but beyond recall except in the presence of its first cause, the great-coat.