The _Jerboas_ are, perhaps, the most singular of all the rodents. They are noted for having the hind legs much longer than the fore ones--in fact, being shaped very much like the kangaroos--of which they might be termed Lilliputian varieties, were it not that they lack the pouch, which distinguishes these curious creatures. Like the kangaroos, they use their fore-feet only to rest upon. When in motion, or desirous of passing quickly over the ground, they make use of their hind-feet only: proceeding by long leaps or jumps, and sometimes springing to the distance of twelve or fifteen feet. Their tails being long and slender, were supposed _not_ to assist them in this operation; but an experiment made by a cruel Frenchman--that of cutting off these appendages--proved that a considerable portion of the jumping power is derived from the tail. Africa and Asia are the head-quarters of these quadrupeds--the most noted species being the Jerboas of Egypt, and the Leaping Hare of the Cape. They dwell in sandy deserts--burrowing in communities like the marmots. In America there are no true jerboas: they are there represented by the Jumping Mice of Labrador and the Hudson's Bay Territory; which resemble the jerboas in almost everything except size, the jumping mice being much smaller animals. _Field Mice_ and _Dormice_ are other kinds of small rodents, differing from the common kind of mouse; but the habits and appearance of these little quadrupeds are well-known. The _Beaver_ and _Musk-rat_, or _Musquash_ of America, are usually classed among the rat tribe; but these animals, for many reasons, deserve to stand apart and form a group of themselves. With regard to the shrew-mice and moles, there is less reason for separating them from other mice; and we shall speak of them in this connection. The _Moles_ are known to be the best burrowers in the world: since they can pass under the surface of the ground as fast as a man can dig after them, or even faster. In England, the common mole is well-known--too well, in fact--for it is the very pest of the farmer; and the damage done by it to the herbage is very considerable indeed--of greater amount than that occasioned by any other wild animal. In America, where there are several species of moles, their habits are similar; and the common American mole is very like its European congener in every respect. But there are two or three species found in North American countries very different from either; and the most singular of all is that known as the Star-nosed Mole. This creature has the cartilage of the snout extended into five or six branches, that radiate from each other, like spokes of a wheel, or the points of a star--hence the name of star-nosed mole. The use of this singular appendage is not clearly understood; and, indeed, it would appear to be an obstruction to the natural requirements of the animal. No doubt, however, it has its purpose--though that purpose be unknown to us.