We grant that a great many creatures, which when seen in a menagerie appear very conspicuous, are the reverse of conspicuous when standing motionless amid their natural surroundings. As Beddard has pointed out, it is often not easy to find a sixpenny piece which has been dropped on the carpet, but the reason for this is, not that the coin is protectively coloured, but that any small object, no matter how coloured, is difficult to distinguish amid a variegated environment. The assumption of a white winter coat by many organisms that live in northern latitudes has been cited, again and again, as showing how important it is for an animal to be protectively coloured. If, it is urged, those creatures that live in lands which are covered in snow for half of the year have become white in winter by the action of natural selection in order to escape their foes, it is obviously of paramount importance to all creatures that they should be cryptically coloured. Popular books on natural history convey the impression that during winter the snow-clad, ice-bound Arctic regions are peopled by a fauna whose fur or hair rivals in whiteness the snowy mantle of the earth. The impression thus conveyed is misleading. It is true that an unusually large percentage of the animals that inhabit the polar regions are white in winter, but the majority of the creatures which dwell there do not assume the white garb of winter. As the fauna of the polar regions is a small one, we are able to give lists of all the birds and mammals which dwell in the Arctic and the Antarctic regions. We have arranged these in in three columns. In the first are placed those creatures which are white throughout the year, in the third those that retain their colour through the winter, while the middle column contains those forms which change their colouring with the season. ARCTIC FAUNA. Mammals. White. Polar Bear. Arctic Fox (some individuals). White Whale or Beluga. Changing with the Seasons. Arctic Fox (most individuals). Arctic Lemming. Stoat. Weasel. Blue Hare. Coloured. Arctic Fox (sometimes). Reindeer. Musk-ox. Glutton. Moose. Sable. Seals. Walrus. Narhwal. Greenland Whale. Birds. White. Ivory Gull. Snowy Owl. Gyrfalcon. Snow Goose. Changing with the Seasons. Black Guillemot. Ptarmigans. Snow Bunting (whitest in summer!) Razorbill. Little Auk (throat only becomes white). Coloured. Sea Eagle. Greenland Redpoll (very pale). All Arctic Geese and Ducks other than Snow Goose. Raven. Cormorant. Brunnich’s Guillemot. Puffin. Fulmar Petrel. Ross’s Gull. Glaucous Gull (very pale). Sandpipers.