A new theory has been broached to explain the migrations of the Norway lemming, a variety of field mouse. Every few years an immense body of these animals leave their habitat and proceed westward, attacking every obstacle in front in preference to flanking it, until it reaches the sea, which the little animals boldly enter, only to perish there. No conceivable advantage to the lemming is known to have ever resulted from these long and arduous marches. The losses in swimming large rivers, from fire,
the attacks of predatory animals, hunger, and fatigue, are so great that but few reach the sea, and the remnant always perish there. Mr. W. Duppa, who has studied the habits of these animals for ten
years, now suggests that they are moved by an hereditary instinct, and that their prehistoric home was some country west of Sweden, and now covered by the Atlantic.
According to him, says "Nature," the migration is not all completed in one year, as formerly supposed, nor do they, as stated, form processions and cut their way through obstacles; but, breeding
several times in the season, they gather in batches, and at intervals make a move westward. Their pugnacity, he states, is astonishing, and the approach of any animal, or even the shadow of a cloud,
arouses the anger of this small creature like a guinea pig, and they back against a stone or rock uttering shrill defiance. Our author found, in most examples, a bare patch on the rump, due to their
rubbing against the said buttress of support when at bay. He wonders why a bare patch, and not a callosity, should not result from this innate, apparently hereditary habit.
76. Mr. Duppa is probably a(n):