Some animals, especially those which prey upon serpents, seem to be proof against their bites. The Ichneumons or Mangoustes of Africa and Asia have long been celebrated for their immunity, and veritable stories have been narrated of their having recourse to some herb, when bitten, after which they successfully renewed the attack. Percival, in his account of Ceylon, relates that a Mangouste placed in a close room where a venomous serpent was, instead of darting at it, as he would ordinarily have done, ran peeping about anxiously seeking some way of escape; but finding none it returned to its master, crept into his bosom, and could by no means be persuaded to face the snake. When, however, both were removed out of the house into the open field, the Mangouste instantly flew at the serpent, and soon destroyed it. After the combat the little quadruped suddenly disappeared for a few minutes, and again returned. Percival concludes, not unreasonably, that during its absence, it had found the antidotal herb, and eaten of it. The natives state that the Mangouste resorts on such occasions to the _Ophiorhiza mungos_, whose root is reputed a specific for serpents' bites. This is a Cinchonaceous plant, so intensely bitter that it is called by the Malays by a name which signifies earth-gall.[189] Captain Forbes in his interesting account of Dahomey, alludes to these combats, which he says he has witnessed in India. He says that the serpent (Cobra) has usually the advantage at first, but the Mangouste retreating, devours some wild herb, returns and presently conquers. Sir Emerson Tennent inclines to refer the immunity of the Mangouste to an inherent property. He remarks that the mystery of its power has been "referred to the supposition that there may be some peculiarity in its organisation which renders it _proof against_ the poison of the serpent. It remains for future investigation to determine how far this conjecture is founded in truth; and whether in the blood of the Mongoos there exists any element or quality which acts as a prophylactic. Such exceptional provisions are not without precedent in the animal economy: the hornbill feeds with impunity on the deadly fruit of the _Strychnos_; the milky juice of some species of _Euphorbia_, which is harmless to oxen, is invariably fatal to the zebra; and the tsetse fly, the pest of South Africa, whose bite is mortal to the ox, the dog, and the horse, is harmless to man and the untamed creatures of the forest."[190] Our own hedgehog possesses the privilege of being unharmed by the venom of the viper, as is manifest in its frequent contests with it. Mr Slater has frequently seen combats between these animals, which always terminated in favour of the hedgehog. The latter seemed perfectly regardless of the many bites it received on the snout.[191]