What is the rhyme scheme of Jabberwocky?

In the first, second, fourth, and seventh stanzas the rhyme scheme is a, b, a, b. In the third, fifth, and sixth stanzas, the rhyme scheme is a, b, c, b; however, there is an internal rhyme into the third line: "he" and "tree" "dead" and "head" "day" and "Calay!"