Arthur H. Lamont, in charge of the meteorological office at Fort Churchill, gave me information concerning Caribou that he had seen during a plane flight from that point to Edmonton on March 18, 1947. At midday he had sighted hundreds, in bands averaging 20 to 30 individuals, on some little lakes, averaging a quarter of a mile in diameter, near the southwestern end of Reindeer Lake. The animals were right in the middle of the frozen lakes (evidently for a noonday rest), and some of them were lying down. They paid no attention to the plane at a height of 6,000 feet, but were frightened when it came down to 200 feet. This was the only area where Caribou were sighted during the entire flight. Duncan A. McLeod, of Winnipeg, informed me that he had seen thousands and thousands of Caribou on April 16, 1941, while he was flying from Isle à la Crosse to Beaverlodge on Lake Athabaska. They were nearer to Lake Athabaska than to the starting-point. They were congregated on frozen lakes about the middle of the day. “Their nomadic migrations during the past 10 years have brought caribou herds during winter months to northwestern Ontario (Little Sachigo Lake); central Manitoba (Cormorant, Cross, and Island Lakes); northern Saskatchewan (Churchill River); northeastern Alberta (Clearwater and Athabaska Rivers and Lake Claire)” (Banfield, 1949: 478, fig. 1). _Spring migration in the Churchill region_ The Hudson Bay Railway is perhaps the only one in North America from which Barren Ground Caribou of the present subspecies have been seen. On May 21, 1947, a passenger reported three or four of the animals near Mile 326, between Gillam and Amery. Farther north, between Herchmer and Chesnaye, the railway passes for perhaps 30-40 miles through the western edge of a tundra area, interspersed with small spruce timber; this is known as the “Little Barrens.” It was a thrilling experience to see my first Caribou here, during a period of three-quarters of an hour on the afternoon of May 21, from Mile 453 to about Mile 475. There were eight bands, varying in number from 2 to 60 or 70 and averaging about 20 individuals. The first and largest band was loping away from the train, at a distance of perhaps 350 yards. A band of 9 or 10, at about 250 yards, exhibited both a trotting and a loping gait. Others, as far off as half a mile or a mile and therefore less alarmed, seemed to content themselves with trotting. They maintained a noticeably close formation while fleeing from the train. Yearlings, appearing only about half the size of the adults, were readily distinguishable. The animals were in the midst of their spring migration and were evidently moving in a general northerly direction over the snow-covered Barrens. The ice of the small lakes was still solid enough for the Caribou to trot over it.