When reduced to scale, the large tracks on the left side are life size, showing the animal making the ordinary bounds of about 3 inches between each set of tracks. In speeding, the space may increase to 12 inches. The tail usually shows in the deermouse track, and this, with the pairing of the fore paws, is a strong characteristic (see pages 521 and 530).] =THE LARGE WEASELS, OR STOATS= (=Mustela arcticus= and its relatives) (_For illustration, see page 554_) The weasel family includes not only the true weasels, but numerous other carnivores, as the sable or marten, mink, ferret, skunk, and land and sea otters, all of which rank among our highly valued fur-bearers. The large weasel may be distinguished from others of its family by the small size and the snakelike proportions of the flattened and pointed head, combined with a long, extremely slender neck and body and a comparatively long tail. The best known of these animals are the stoat of the northern parts of the Old World (_Mustela erminea_) and its close relative in northern North America (_Mustela arcticus_), the winter skins of which furnish the famed ermine, once sacred to the trappings of royalty. The northern weasels are strongly marked by their habit of changing their brown coat to one of snowy white at the beginning of winter. To the south the change becomes less complete as the winter snows decrease, and south of the limit of snow the brown coat is retained throughout the year. The time of change depends on the coming of the snow and varies with the year, and the time of resumption of the brown coat in spring depends in the same way on the season. The white winter coat of the larger and medium-sized species is accompanied by a strongly contrasting jet black tip to the tail. Weasels are circumpolar in distribution and occupy nearly all parts of Europe, Asia, and North and South America, the greatest number and variety of species occurring in North America. Surprisingly enough, the largest of these eminently northern animals is found in the forests of the American tropics. The Arctic weasel ranges to the northernmost polar lands of North America, where its presence has been recorded many times by ice-bound explorers. Other species are more or less generally distributed over the remainder of the continent. In Mexico I have found them from sea level to above timberline, at more that 13,000 feet altitude on the high volcanoes. The strong personality of the weasels as a group is based mainly on their extraordinary celerity of movement, their courage, and their insatiable desire to kill. They are not satisfied with supplying the call for food, but whenever opportunity arises kill from sheer lust of slaughter.