Meet the Honorable Mr. Sandwich! He has more forms than John Barrymore has faces. Today, at the home of Mrs. Smith, he may be made from brown whole wheat bread with distinctive pink for filling. Tomorrow, at the home of Mrs. Jones, he may present himself in white bread with red or green or rainbow trimmings. And the shapes this young and honorable character may assume! He can be moon shaped, square, round, diamond - in fact, he can make use of every dimension except Mr. Einstein's fourth.