The rat multiplies very fast, but the increase of the long-tailed field-mouse is more considerable. The latter brings forth more than once a year, and generally nine or ten at a time, while the rat seldom produces more than five or six. A peasant, on my estate, took twenty-two out of one hole, consisting of two dams and twenty young ones. This animal is very generally diffused over Europe. It is found in Sweden, and is called by Linnæus, _mus cauda longa, corpore nigro flavescente, abdomine albo_. It is very common in France, Italy, and Switzerland. Gesner calls it _mus agrestis major_. It is also in Germany and England, where it is called the field-mouse. Its greatest enemies are the wolf, fox, marten, birds of prey, and its own species. THE WATER-RAT. This animal is about the size of a common rat, but in habits and disposition more resembles the otter than the rat. Like the otter it frequents fresh water; is found on the borders of rivers, rivulets, and ponds, and seldom feeds on any thing but fish, though he will sometimes eat frogs, water insects, and even the roots of plants. He has not, like the otter, membranes between his toes; an error which originated with Willoughby, and has been copied by Ray and other naturalists. Though every toe is separated, he swims with facility, keeps a long time under water, and carries off his prey to eat upon the grass or in his hole. Sometimes he is surprised in his hole by fishermen who are searching for craw-fish, whose fingers he bites, and then plunges into the water as his only place of refuge. His head is shorter, his nose broader, his hair more erect, and his tail much larger than the common rat. Like the otter he avoids large rivers, or rather those which are too much frequented. The dogs pursue it very furiously. He is never found in houses or barns, nor does he wander so far from the borders of the waters as the otter, which is sometimes found at a league distant upon land. The water-rat does not frequent high grounds nor dry plains but in moist and marshy valleys they are very numerous. The females come in season about the close of winter, and bring forth in April, generally having six or seven in a litter; they may probably bring forth oftener than once a year, but of this we have no certain knowledge. Their flesh is not absolutely bad, being eaten by the peasants in catholic countries during Lent, as well as that of the otter. This species is found throughout Europe, the very extremities of the north excepted. If Bellon may be believed they inhabit the banks of the Nile, but the figure he gives of it has so little resemblance to our water-rat, that there is great reason to suppose them different animals. THE CAMPAGNOL.