Charles also gave me an account of a remarkable sort of play between a Red Fox and a small buck Caribou. He had witnessed it in September, 1943, about 18 miles north of Windy River, from a distance of half a mile. The Fox would approach the Caribou closely; the latter would then walk up to the Fox, which would retreat, not allowing the Caribou to come close enough to touch it. Neither animal was afraid of the other. They kept up this performance for about 5 minutes. The Fox then went among some bushes, where the Caribou tried to follow it. The larger animal was still there, feeding, when Charles passed on out of sight. He regarded the whole performance as a matter of playfulness. His recital put me in mind at once of a slightly similar play between a Newfoundland Caribou and a Red Fox, as recorded by Millais (1907: 302-303). Stefánsson (1921: 623-624) describes a game of tag between an Arctic Fox and several yearlings of _Rangifer pearyi_ on Melville Island. _References._--Blanchet, 1925: 34; Birket-Smith, 1929(1): 101; Critchell-Bullock, 1930: 143; Munn, 1932: 278; Ingstad, 1933: 90, 157-159; Freuchen, 1935: 128; Banfield, 1951a: 36. _Relations to Wolves_ Aside from man, the principal predatory enemy of the Barren Ground Caribou is undoubtedly the Wolf. A comparison of a distributional map of Caribou by Banfield (1949: 479, fig. 1) with a distributional map of Wolves by Goldman (1944: 414, fig. 14) indicates that the latter species is a considerably more plastic animal. No less than six subspecies of Wolves seem to occur in parts of the currently recognized range of a single subspecies of Caribou (_Rangifer arcticus arcticus_), as follows: _Canis lupus arctos_, Prince of Wales and Somerset islands; _Canis lupus manningi_, Baffin Island; _Canis lupus bernardi_, Victoria Island; _Canis lupus hudsonicus_, Keewatin, eastern Mackenzie, northern Manitoba, and northeastern Saskatchewan; _Canis lupus mackenzii_, northern Mackenzie; _Canis lupus occidentalis_, southern Mackenzie and northern Alberta and Saskatchewan.