Human blood groups are an example of discontinuous variation. In the ABO blood group system, only four blood groups are possible - A, B, AB or O.

ON September 24, some years ago, I collected at Mesilla, New Mexico, four examples of a wild bee of the genus Epeolus, the species being probably identical with Epeolus bardus of Cresson. In every ...

At the instigation of Bateson (1900), who wished to assemble examples of discontinuous variation, the records were brought together (Barrett, 1901; Doncaster, 1906) to provide a starting point for ...