The patterns of serological polymorphic variety in a group of Oxfordshire populations are related to previously made demographic predictions that the different villages and social classes might be expected to be genetically homogeneous if movement were the main factor determining genetic structure. The predictions are largely fulfilled though there remains a residual pattern of variety which is detectable when all the systems tested are considered together by "genetic distance" examination, and in the case of the geographic variation this pattern reflects the comparative magnitude of the exchanges between the different villages.