Quaestiones Naturales

DOGS eat grass, to make them vomit bile. Swine seek craw-fish, because the eating of them cures the headache. The tortoise, when he has eaten a viper, feeds on wild marjoram. They say, when a bear has surfeited himself and his stomach grows nauseous, he licks up ants, and by devouring them is cured. These creatures know such things neither by experience nor by chance.

Whether, as wax draws the bee, and carcasses the vulture afar off by the scent, do craw-fish so draw swine, wild marjoram the tortoise, and ants the bear, by smells and effluvia accommodated to their nature, they being prompted altogether by sense, without any assistance from reason? Or do not the temperaments of the body create appetites in animals, while diseases create these, producing divers acrimonies, sweetnesses, and other unusual and absurd qualities, the humors being altered; as is plain in women with child, who eat stones and earth? Therefore skilful physicians take their prognostic of recovery or death from the appetites of the sick. For Mnesitheus the physician says that, in the beginning of a disease of the lungs, he that craves onions recovers, and he that craves figs dies; because appetites follow the temperament, and the temperament follows diseases. It is therefore probable that beasts, if they fall not into mortal diseases, have such a disposition and temper, that by following their temper they light on their remedies.