The vegetable kingdom, that provides food for nine-tenths of all living creatures, abounds with an endless variety of edible fruits, seeds, and herbs, but also with injurious and even deadly products, often closely resembling the favorite food-plants of animals; which in a state of Nature are nevertheless sure to avoid mistake, and select their food by a faculty of recognizing differences that might escape the attention even of a trained botanist. The chief medium of that faculty is the sense of smell in the lower, and the sense of taste in the higher animals. In monkeys, for instance, the olfactory organs are rather imperfectly developed, and I have often seen them peel an unknown fruit with their fingers and then cautiously raise it to their lips and rub it to and fro before venturing to bring their teeth into play. The preliminary test, however, always sufficed to decide the question in a couple of seconds. The Abyssinian mountaineers who catch baboons by fuddling them with plum brandy have to disguise the taste of the liquor with a large admixture of syrup before they can deceive the warning instincts of their victims. Where copper mines discharge their drainage into a water-course, deer and other wild animals have been known to go in quest of distant springs rather than quench their thirst with the polluted water. That protective instincts of that sort are shared even by the lowest animals is proved by the experiment of the philosopher Ehrenberg, who put a drop of alcohol into a bottle of pond water, and under the lens of his microscope saw a swarm of infusoria precipitate themselves to the bottom of the vessel. Animals in a state of Nature rarely or never eat to an injurious excess; the apparent surfeits of wolves, serpents, vultures, etc., alternate with long fasts, and are digested as easily as a hunter, after missing his breakfast and dinner, would be able to digest an abundant supper. Instinct indicates even the most propitious time for indulging in repletion. The noon heat of a midsummer day seems to suspend the promptings of appetite; cows can be seen resting drowsily at the foot of a shade-tree; deer doze in mountain glens and come out to browse in moonlight; panthers cannot afford to miss an opportunity to slay their game at noon, but are very apt to hide the carcass and come back to devour it in the cool of the evening.