Plutarch's Natural Questions (26-30)

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.

Is it because the changing of the sweet must into wine is concoction, but cold hinders concoction, because this is caused by heat? Or, on the contrary, is the proper taste of the grape sweet, and is it then said to be ripe, when the sweetness is equally diffused all over it; but does cold, not suffering the heat of the grape to exhale, and keeping it in, conserve the sweetness of the grape? And this is the reason that, in a rainy vintage, must ferments but little; for fermentation proceeds from heat, which the cold does check.

Is it because his teeth stand so far within his head, that he cannot well come at the thread? For his lips, by reason of their thickness and largeness, meet close before. Or does he rather rely on his paws and mouth, and with those rend the toil, and with this defend himself against the hunters? His chief refuge is rolling and wallowing; therefore, rather than stand gnawing the toil, he rolls often about, and so clears himself, having no occasion for his teeth.

Is it because very fat goats (τράγοι) are less able to procreate, nay, scarce able to use coition, by reason of their fatness Seed is the superfluity of the aliment which is allotted to the body: now, when either an animal or a plant is of a very strong constitution and grows fat, it is a sign that all the nourishment is spent within, and that there is little and base excrement, or none at all.