The traditional sport of hunting the "gamecock" is the foundation of the word "Cocker". The term "Cocker" denotes those spaniels which were used for hunting this bird. Many years ago hunting dogs were classified according to size. Those over 25 pounds were classified as Field Spaniels and those under 25 pounds were classified generally as Cocker Spaniels. Selective breeding of Spaniels and other hunting breeds in the nineteenth century began to distinguish and discriminate between the different types of Spaniels.