“The amphibian meadow-mouse is commonly known by the name of water-rat. We can easily tell it from the black rat, which is of about the same size, by its red coat, its short tail (which is not quite half the length of its body), and its larger and less pointed head. It burrows under the banks of streams, ditches, and marshes, where it feeds chiefly on roots, but does not disdain small fish when it can catch them. It is a good swimmer and diver. Sometimes it makes its way into kitchen-gardens, where it does the same sort of harm as the underground meadow-mouse, and into orchards, where it gnaws the base of young trees. “The lemming is never seen around here. It frequents the coasts of the Arctic Ocean in Norway and Lapland. I will tell you something about it on account of its curious way of traveling from one country to another, of which our meadow-mouse offers us a far less striking example. The lemming, with its very short and hairy tail, its big head, and its stocky body, has the appearance of a small rabbit. Its coat is red marbled with black and brown. “At the approach of severe cold weather, and sometimes with no apparent reason, the lemmings leave their haunts in the high mountain chains of Norway and set out on a long journey toward the sea. The emigrating horde, composed of myriads of individuals, trot in a straight line over all obstacles, never allowing themselves to be turned from their course. In traveling in a line, one after another, says Linnæus, the great Swedish naturalist, they trace straight parallel furrows, two or three fingers deep and several ells apart. They devour everything eatable that obstructs their passage, all roots and herbage. Nothing turns them from their course. Let a man appear in their path, and they slip between his legs. If they come to a haystack they gnaw a tunnel through it; reaching a rock, they skirt it in a semicircle and then resume their original direction. Should a lake be encountered on their route, they swim across it in a straight line, however wide it may be. If a boat is in their way in the middle of a body of water, they clamber over it and jump into the water again on the other side. A swiftly flowing river does not stop them: they plunge into the foaming current even if they all perish.” “They must be very obstinate,” said Emile, “to prefer to drown rather than turn their procession out of a straight line.” “Animals sometimes show these examples of obstinacy, which we cannot understand, but which might easily be explained if we knew the motives that make them act thus. Perhaps by deviating from a straight line the lemmings might lose their way, a way provided with no finger-posts, but indicated simply by instinct. However, we will leave them to pursue their long pilgrimage, from which few will return, so numerous are the dangers and the enemies awaiting them on the way. Let them cross their rivers and lakes while we return to the rodents of France.