Ciliate conjugation is a sexual phenomenon that results in genetic recombination and nuclear reorganization within the cell. In most ciliate groups, however, the cells separate after conjugation, and both form new macronuclei from their micronuclei.
Before the bun, hamburgers are said to have been served between two pieces of bread. In fact, a ground beef patty was known as Hamburger steak (first mentioned in an American cookbook in 1891); when this was put between bread or in a bun it was called a Hamburger sandwich.
White Castle traces the origin of the hamburger to Hamburg, Germany with its invention by Otto Kuase. However, it gained national recognition at the 1904 St. Louis World's Fair when the New York Tribune referred to the hamburger as the innovation of a food vendor on the pike.