a much more noble animal--to the _beaver_,[6] friend Brush, though perhaps you have never heard of such a creature. [5] The common brown rat, which has now been an inhabitant of this island for about one hundred years, is often improperly called the "Norway rat," as if it came originally from that country; whereas, it was quite unknown there when it first received that name. Pennant believes that it was brought over in merchant-vessels from the East Indies. It is even supposed, that the old English black rat, as it is called, is not originally a native of this island, as no mention is made of it in any author earlier than the middle of the sixteenth century. [6] The characters of the teeth, the form of the body, and the habits of the water-rat, fully justify its removal from the genus _mus_, to which the common rat belongs, and indicate a pretty close affinity to the beaver. Linnæus himself appears struck with this, for though in his _Systema Naturæ_ he has placed the water-rat in the genus _mus_, in a subsequent work he has removed it to that of _castor_. Well, well, we must not expect too much from people who have never had an opportunity of learning. I could tell you a good deal about this relation of the water-rat, this clever fellow called the beaver, and about the famous wooden houses he makes of the trunks and branches of trees. But I declare I must fly home, and see how Mrs. Leatherwing is getting on. Oh! stop a minute, though; I forgot one thing. Perhaps _you_ don't believe that I can run on a level surface, or raise myself from it, as you may never have seen me do it. Look here, then! So saying, the funny little creature made what he called a _run_, along the large branch upon which Brush was seated, and at the end of this _run_ of two or three feet in length, he gave a sort of a little spring into the air, and instantly spreading his beautiful wings, he sailed away from the tree, saying, "Good bye, Brush! what d'ye think of that, eh?" But the squirrel did not return the farewell, for when he saw the very ridiculous manner in which his friend shuffled along, while he performed the feat which he called _running_, he was seized with such a fit of laughter that he could make no reply, and he was even obliged to hold fast, lest he should fall off the branch. When he had recovered from his merriment, he began to talk to himself, in an unusually grave and moralizing strain.