1 lb. butter, softened
2 c. sugar
8 lg. eggs
4 c. flour
4 c. blueberries
4 tbsp. minced lemon rind

Preheat oven to 300 degrees. Lightly butter a 6 cup tube pan. In large bowl combine butter and sugar; cream until light and fluffy. Beat in eggs, one at a time. Gently fold in all but 1 tablespoon of the flour, 1/4 cup at a time. Toss blueberries with lemon rind and remaining 1 tablespoon of flour. Fold into batter and pour into pan. Bake for 1 hour and 20 minutes or until cake tests done. Cool completely; unmold and let stand overnight before serving.