Among the most popular family of tile-based games is the domino. The game is characterized by a series of "ends" in which players attempt to make pairs. Players begin with seven tiles drawn from stock. When one of the tiles is tipped, it falls, causing the next domino to fall. The player who has the lowest number in his hand wins. There are a variety of games based on the domino, including solitaire, trick-taking, and scoring games. The game began in Italy in the early 18th century, and the name of the game, dominus, was first recorded in the Dictionnaire de Trevoux in 1771. The game spread to France in the mid-18th century, and by the late 1700s it had spread to England. The most common type of domino game is the scoring game. In this game, the player attempts to make pairs, attempting to divide five or three into two tiles. When the player has done this, the game ends. Typically, the running total score is kept on a cribbage board. In competitive leagues in the British Isles, the player who has the lowest number in his hand scores one point. There are also some more complicated games based on the domino. For example, there is the game of Che Deng, which is played with a double 18 domino set, which contains 190 dominos. In this game, each player tries to create a sequence of numbers, with the best sequence resulting in the highest score. The game can be played with a single player, or with several players. There are also dominoes that are made out of wood, ivory, or mother of pearl oyster shell. Traditional European dominoes are made out of dark hardwoods such as ebony. The most common domino set is the double six set, which contains 28 tiles. This set has unique pieces for each possible combination of two ends, with zero to six spots on each end. There are also dominoes made out of silver lip ocean pearl oyster shell. These are characterized by having no Chinese suit distinctions. The most common set has 28 tiles, but there are also double nine sets that contain 55 tiles. Dominoes are also used for scientific research. For example, they can be used to study nerve cells. By studying the structure of nerve cells, you can learn how nerve impulses travel through the body. The falling dominoes may represent a firing neuron. It is possible to study nerve cells by removing a domino, which is like a severe nerve injury. The nerve impulse cannot travel past the site of the injury. The nerve cell then redistributes the ions to a resting state. Other domino games include trick-taking and layout games. The layout game involves placing the tiles on an edge of the board. There are also domino games that involve laying out the tiles to form a "pupai" or a tiger. These are often called the Chinese version of the domino.