Just as the $1 and $2 definitive postage stamps issued in March 1972 remind us of our urban centres, Canada's new medium value denomination remind us of the tremendous variety in our nation's terrain. The immensity and diversity of Canada are almost incomprehensible; few other nations have the challenge of the seas, the woodlands, the prairies, the mountains and the north. Our country, a land of breathtaking beauty, has inspired Reinhard Derreth, of Vancouver, to create these designs which capture something of the vastness and beauty. Symbolic of the vastness of the Canadian North are the two polar bears pictured on the 25c. issue. The polar bear, or ice or white bear as it is sometimes called, ranges from Victoria Strait east to Labrador and south to James Bay. A good swimmer, it will often travel great distances from its ice floe home in search of the seals, fish, birds and young walruses on which it feeds. Polar bears, a traditional source of food and clothing for the Eskimos, have in recent years been regarded by many as an endangered species.