Lat. issula in Plauto e l'assimilazione del gruppo -ps- nel latino parlato
The -ps- > -ss- regressive assimilation is admittedly part of a general weakening drift of syllabic codas in late latin, as in the cases of -kt- > -tt- / -xt-, -ks- > -ss- and so forth. The early Plautinian noun issula “mistress” (< ipsula) in a corrupt passage of Cistellaria (v. 450) is traditionally interpreted as the very first occurrence of this well-known vulgar latin phenomenon (cf. ital. esso, scrisse etc.). After a thorough inspection of all the available evidence, both in the inscriptions and in the literary texts, three points should be underlined.