Jerboas are very common in Egypt and other parts of North Africa, and live in burrows which they dig in the sandy soil. In order to enable them to obtain a firm foothold on the slippery sand, the soles of their feet are covered with long hairs, which also prevent them from being scorched by contact with the heated ground. But as a rule they do not come out of their burrows until the evening, when the sun is not so powerful as it is during the middle of the day. They feed upon grasses and dry shrubs; but how they find enough to eat in the desert places in which they live is rather hard to understand. Many different kinds of jerboas are known. The best known, the common jerboa, is about as big as a small rat, and has a tail about eight inches long. In color it is so much like the sand that from a few yards away it is almost impossible to see it, even when it is skipping about. THE HAMSTER This is a queer little rodent which is found very plentifully in Germany, and also in many districts between that country and Siberia. It is a rather stoutly built animal, and measures nearly a foot in length including the tail, which is about two inches long. In color it is generally light brownish yellow above and black beneath, with a black stripe on the forehead, a yellow patch on the back, and white feet. But hamsters are by no means all alike, and some are entirely black, some pied, and some entirely white. You remember how dormice make summer and winter nests. In the same way, European hamsters make summer and winter burrows. The summer burrow is quite a small one, not more than a foot or two deep, with a small sleeping-chamber at the bottom. But the winter one is very much larger, for it is not only six feet long at least, with quite a big sleeping-chamber, but there are from one to five side chambers as well, which are used as granaries. In these the animal stores up vast quantities of grain, peas, and beans, as many as sixty pounds of corn having been taken from the burrow of a single hamster, and a hundredweight of beans from that of another. About the middle of October it stops up the entrances to its home, and passes into a state of hibernation, in which it remains till the beginning of March. For about a month longer it still remains in its burrow, feeding on its stores and provisions, till early in April it resumes its active life, and returns to its summer habitation. Of course hamsters are terribly destructive in cultivated land, and large numbers are destroyed every year. In one district alone nearly a hundred thousand have been killed in a single season, while an enormous quantity of grain was recovered from their tunnels. WATER-VOLES