Decrease of local American stocks of Caribou, and consequent suffering of native populations who had in past generations depended upon these animals for a major portion of their food supply, have led to introduction of foreign Reindeer in several regions of North America, from Newfoundland and Labrador in the east to Alaska in the west. The persons responsible were doubtless inspired by high humanitarian motives; but it is doubtful if they could have thoroughly considered or foreseen the serious biological consequences of their efforts. In Alaska, importation of domesticated Siberian Reindeer began in 1892. By the 1930’s the herds had increased to an estimated total of 600,000. For various reasons, however, the industry has so far declined that by 1949 the total number of Alaskan Reindeer had become reduced to about 28,000 head. Disinclination of Eskimos for reindeer-herding and mixture of their stock with wild Caribou were important reasons for this decline. (Lantis, 1950.) From the biologist’s point of view, the most unfortunate result was the large-scale interbreeding with the native Grant’s Caribou (_Rangifer arcticus granti_) and the progressive extermination of that fine animal in a pure form by dilution with inferior alien blood. Among Alaskan Reindeer, “constant inbreeding has led to a noticeable reduction in the prolificness of the females, and degeneration is to be observed in many herds” (Hewitt, 1921: 323). In 1908 Dr. Wilfred T. Grenfell brought 300 Lapland Reindeer to Newfoundland. After some years they were transferred to the north shore of the Gulf of St. Lawrence and finally to the island of Anticosti. (Hewitt, 1921: 324-328; Seton, 1929, +3+: 92.) In 1911, 50 of these Reindeer were shipped from Newfoundland to the Slave River region. Most of them escaped (probably to contaminate the local stock of Caribou), and by 1916 the last survivor of this band in captivity had succumbed (Hewitt, 1921: 329-330). “A large part of the reindeer in Alaska are south of the Arctic Circle on the comparatively mild shores of Bering Sea, where there are several months of open tidewater navigation; vegetation is more luxuriant [than in Arctic Canada] and conditions easier in general. There the reindeer were introduced into a country where the wild caribou had been virtually exterminated, and a large native population were anxious to take up a new mode of support. The percentage of profits has appeared unduly large in Alaska because statisticians have been unable to take into account the value of the services of a large body of devoted missionaries, government teachers, and other unselfish persons who put their best efforts into years of unpaid extra work to make the reindeer successful and beneficial to their charges.