Summary

Edmund William Gosse 1911 Encyclopædia Britannica, Volume 26… (1911)

It is impossible, however, to break off here, since there is no rhyme to forte, which has to be supplied twice in the succeeding terzina, where, however, a fresh rhyme, trovai, is introduced, linking the whole to a still further terzina, and so on, indefinitely. The only way in which a poem in terza rima can be closed is by abandoning a rhyme, as at the end of Canto 1 of the Inferno, where no third rhyme is supplied to Pietro and dietro. Boccaccio wrote terza rima in close following of Dante, but it has not been a form very frequently adopted by Italian poets.
Source: Wikisource

Edmund William Gosse 1911 Encyclopædia Britannica, Volume 26… (1911)

The serventese incatenato of the latter was an arrangement of triple rhymes, and unquestionably appears to have a relation with terza rima; this connexion becomes almost a certainty when we consider the admiration expressed by the Tuscan poets of the 13th century for the metrical inventions of their forerunners, the Provençals.
Source: Wikisource

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