[Illustration: FIG. 4. Skull, antlers, skin, and hind quarter of the same Caribou being transported to camp along the Camp Ridge. August 17, 1947.] [Illustration: FIG. 5. Anoteelik and Mike preparing to bring in a load of caribou meat with dogs and travois. Windy River post, August 19, 1947.] [Illustration: FIG. 6. Anoteelik and Mike pegging out caribou hides to dry on a gravelly ridge near the mouth of Windy River. August 23, 1947.] [Illustration: FIG. 7. About 75 Caribou (bucks, does, and fawns) at a rapid on Little River. August 25, 1947.] [Illustration: FIG. 8. About 22 Caribou crossing Little River at a rapid. Chiefly does and fawns, with several bucks bringing up the rear. August 26, 1947.] By October 6 there were 6 inches of snow on the ground, and on the following day 200 Caribou swimming southward across Windy Bay may have marked the beginning of the final movement into the timbered country. It appears possible that a considerable fall of snow may have a definite influence in inducing the Caribou to retreat from the Barrens. On a trip from Windy River north to the Kazan River region in September, 1946, Charles Schweder found, during the first 45 miles, that the Caribou were moving north; at the Kazan they were moving south, although some were merely loitering. Northwest of the Kazan, the animals were taking a westward course. During the latter part of his return trip to Windy River, 11 or 12 days later, they had reversed the previous direction and were traveling south. For such a distinct and regular feature in the life cycle of the species as the retrograde autumnal movement there must be some biological explanation. Several possible factors appear reasonably clear. Perhaps we may consider the Barren Grounds the true and preferred home of _Rangifer arcticus_, from which a proportion of the population is driven during part of the year under stress of insect attacks or shortage of food. When the animals begin to enter the woods in August, there is no shortage of food; thus an insect-induced frenzy may possibly be regarded as a potent force driving them southward. In September a state of comparative peace descends upon the caribou world: the current crop of adult insects has subsided; the larvae of warble and nostril flies have not attained the formidable size of the following spring and perhaps are not yet causing any severe discomfort; little or no snow covers up the food supply; the lakes and rivers, still unfrozen, offer a ready way of escape from pursuing Wolves; moderate or even balmy weather gives nature a pleasant mood. In short, both man and beast may well look upon early autumn as the very finest time of year both on the Barrens and in the adjacent wooded country.