He called them earlier or later. The three ages became six periods. The British seized on the concept immediately. Worsaae's earlier and later became Lubbock's palaeo- and neo- in 1865, but alternatively English speakers used Earlier and Later Stone Age, as did Lyell's 1883 edition of "Principles of Geology", with older and younger as synonyms. As there is no room for a middle between the comparative adjectives, they were later modified to early and late. The scheme created a problem for further bipartite subdivisions, which would have resulted in such terms as early early Stone Age, but that terminology was avoided by adoption of Geikie's upper and lower Paleolithic.