_tonan_; the reference appears to be to _Tonantzin_, Our Mother,
otherwise known as Cihuacoatl, the Serpent Woman. She was the
mythical mother of the human race, and dispensed afflictions and
adverse fortune. See Sahagun, _Hist. de la Nueva España_, Lib. I,
cap. 6. The name is a proof of the antiquity of the poem, which is
throughout in the spirit of the ancient religion.