In a small bowl, beat egg whites until stiff; set aside.
In a separate bowl, sift together flour, baking powder, sugar and salt. Beat egg yolks in a medium mixing bowl; add milk and melted butter. Stir egg mixture into dry ingredients; mix until batter is smooth and stir in blueberries. Fold in beaten egg whites. Bake on hot greased griddle.
Makes 12 pancakes.