The Suffixes -aster, -ignus, etc., in Nouns of Relationship

In an article on the Interchange of suffixes -aster, -ignus and -icus (Mod. Lang. Notes, 1909, 241-3), Mr. S. G. Patterson sustains that, in words of step-relationship, in addition to the endings -aster and -ignus (of Lat. privignus), the termination -icus (of Lat. vitricus) survives, not only in Sard. bidrigu, etc. and Rum. vitrigu, etc., but also in O. Fr. serorge, etc. (Godefroy) and in Neapol. matreye and patreye. After considering the diffusion of -aster and -ignus, the author summarizes: “Enough examples have been given to show the constant interchange of -ignus and -aster in these words of quasi-kinship… in several dialects the same stem is found compounded indifferently with either suffix (cf. Venet.)." He doubtless means rather alternation than interchange; for no real interchange is demonstrated: the diffusion of Ven. pareastro is not precisely the same as that of paregno; Boerio limits the first to Chioggia.