MORPHOLOGY AND TAXONOMY 108 Pelage and molt 108 Albinism 112 Foot-glands 112 Mastology 113 Fat 113 Body measurements and weights 114 Measurements of skulls 115 Measurements of antlers 115 Measurements of testes 115 Geographical variation 116 LITERATURE CITED 120 ANNOTATED BIBLIOGRAPHICAL REFERENCES TO _Rangifer arcticus arcticus_ 134 INDEX 161 INTRODUCTION No other large North American land mammal is of such primary importance as the Barren Ground Caribou (_Rangifer arcticus arcticus_) as a source of food and clothing for so many primitive Eskimo and Indian tribes; no other performs such extensive and spectacular migrations; no other may be seen in such vast herds; no other exhibits so close an approach to a Garden-of-Eden trustfulness in the presence of man. And perhaps no other is more worthy of being cherished and safeguarded in its natural haunts for the benefit and enjoyment of future generations. The original valid designation, in technical nomenclature, of the Barren Ground Caribou of the Mackenzie-Keewatin region dates back to 1829, when Sir John Richardson described it in the _Fauna Boreali-Americana_ as _Cervus tarandus_ var. _arctica_. The type locality is Fort Enterprise (about lat. 64° 30´ N., long. 113° W.), on Winter Lake, an expansion of Snare River, Mackenzie. Since the typical subspecies appears to lack a distinguishing common name, it would seem fitting to associate with it the name of its worthy describer; thus, Richardson’s Barren Ground Caribou. The author’s intimate acquaintance with the animal should have enabled him to draw up a somewhat fuller and more adequate description than he did. Previous travelers in the Barren Grounds, among whom Samuel Hearne (1795) was particularly notable, had contributed accounts of the species, without differentiating it from the Lapland Reindeer (_Rangifer tarandus_) or without giving it a distinctive technical name.