LEMMING (No••.. S•ed., 'Dan. lemming, perhaps from Norw. lemja, to maim, but more probably from Lapp louniek, lumina% lemming). (1) A vole or short-tailed rat (Myatt's lemmas) of the subfamily A1'y]c11lIW'P, inhabiting the cen tral mountain chain of Norway and Sweden. Lemmings are about five inches long, and yellow ish-brown, marked with darker spots; and their food consists largely of birch shoots, mosses, grass roots and stalks. ete. In winter they form long galleries under the snow, in their wanderings in search of food. They make a nest in sonic shel tered place out of dry grass and hair, and there the young are born, two broods annually, with about five at a birth.
The circumstance which has made the lemming famous is its so-called 'migration,' the cause of which has never been satisfactorily explained. At intervals ranging from five to twenty or more years, lemmings suddenly appear in enormous numbers in cultivated districts of Norway and Sweden, where ordinarily they do not occur, traveling seaward and not deterred by any ob stacle. They swim the streams and lakes which may lie in their path and keep persistently on ward, until finally the survivors reach the sea, into which they plunge and so ultimately perish. During this migration all sorts of predatory animals follow in their wake, feasting on the unusual abundande of food, while men also slaughter them. as the damage they inflict
on cultivated fields is serious. (See Plate of GornEns.) (2) Besides the Norwegian lem ming, several related animals are given the same name. One of these (Epodes Olonsis) inhabits the An-tie regions of both hemispheres and is very abundant in Northwestern America. It is bright rusty-brown in color and is not known to make Another species schisticolor) inhabits Siberia and is plain slate gray. A closely related animal, the banded lem ming or hare-tailed rat or mouse, is Clinicians torgnotus: it is found in the Hudson Bay country and Greenland. and is remarkable for turning white in winter. The 'false' lemming represents a third nearly related genus, the single speeies of which. Synaptoings rooperi, occurs from Indiana and Kansas northwestward to Alaska. Other American rodents known as 'lemmings' are Lem in us trimucronatus and Dicrostonyx R-ichardsow For these American mice, consult Treble, "A Bio logical Investigation of the Hudson Bay legion, North American Fenno, No. 22 (Washington 3902), and other publications in the same series.