Nearly all animals, from mollusks to men, reason—not once or twice in a lifetime, but the most of them every day and every hour of their existence. In fact, it would be impossible for any animal addicted to moving about, and with a delicate and easily wrecked organism, to long survive in a world like this without that elasticity of action which reason alone can impart. Since they live in the same world-conditions as human beings, and are seeking providence for substantially the same wants, non-human beings manifest reason in the same general directions as human beings do—in the location and construction of their homes and fortresses, in the arrest of their prey, in circumventing their enemies, in overcoming obstacles and surmounting dangers, in protecting and educating their young, in meeting the emergencies of food and climate, in the wooing of mates and the waging of wars, and in the thousand other cases where they are called upon in their daily wanderings and doings to deal with novel and unprecedented situations. When wild geese are feeding there is said to be always one of them that acts as sentinel. This one never takes a grain of corn while on duty. When it has acted awhile it gives the bird next to it a sharp peck and utters a querulous kind of cry, and the second one takes its turn. This is prudence, or forethought, which is a form of reason. When swans are diving there is generally one that stays above the water and watches. Sentinels have alarm sounds of various kinds, which they give to signify ‘enemy.’ ‘Ibex, marmots, and mountain-sheep whistle; prariedogs bark; elephants trumpet; wild geese and swans have a kind of bugle call; rabbits and sheep stamp on the ground; crows caw: and wild ducks utter a low, warning quack.’ In the _Popular Science Monthly_ for March, 1901, is an account of a series of experiments on the intelligence of the turtle made by Professor Yerkes, of Harvard. The turtle was placed in a labyrinth, at the farther end of which was a comfortable bed of sand. It took just thirty-five minutes of wandering for the turtle to reach the nest the first time. But in the second trial the nest was reached in fifteen minutes, and by the tenth trip the turtle was familiar enough with the route to go through in three and one-half minutes, making but two mistakes. The turtle was afterwards placed in a more complex labyrinth, containing, among other features, a blind alley and two inclines. The inclines were puzzles, and it took one hour and thirty-five minutes of aimless rambling for the wanderer to reach its nest the first time. But the fifth trip was made in sixteen minutes, and the tenth in four minutes, which was not far from direct.