 In the book, Mackenzie maintains that the Caucasoid Cro-Magnons who settled in Britain were dark haired and dark eyed, racially akin to the French Basques, Iberians and Berbers of North Africa (p. 25), who he theorised were one of the earliest representatives of the Mediterranean race.This indigenous proto-Mediterranean racial stock was later invaded by another "variety of the Mediterranean race" who initiated the Solutrean culture around 20,000 years ago (p. 50).According to Mackenzie, the Aurignacian and Solutrean peoples of Britain traded in shells with Cro-Magnons of France.