The hide, too, of the hippopotamus is so thick, that lances,[1] even, are turned from it, and yet this animal has the intelligence to administer certain medicaments to itself. The hide, too, of the elephant makes bucklers that are quite impenetrable, and yet to it is ascribed a degree of intelligence superior to that of any quadruped. The skin itself is entirely devoid of sen- sation, and more particularly that of the head; wherever it is found alone, and unaccompanied with flesh, if wounded, it will not unite, as in the cheek and on the eyelid,[2] for instance.