Heat oven to 325 degrees.
Blend milk, lemon juice, rind and egg yolks (save egg whites for meringue).
Pour into pie shell.
Top with meringue made by beating the eggs whites and cream of tartar until frothy.
Gradually beat in sugar and continue beating until stiff and glossy.
Pile on top of filling.
Bake 15 to 20 minutes or until lightly browned.