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.
There have been many claims about the origin of the hamburger, but the origins remain unclear. The popular book The Art of Cookery made Plain and Easy by Hannah Glasse included a recipe in 1758 as Hamburgh sausage, which suggested to serve it roasted with toasted bread under it.