Space curves of genus 7 and degree 8 on a non-singular cubic surface with stable normal bundle (Q1121954)

It has been shown by \textit{D. Perrin} [C. R. Acad. Sci., Paris, Sér. I 299, 451-453 (1984; Zbl 0573.14008)] that curves in \({\mathbb{P}}^ 3\) of degree \(s^ 2-1\) which are linked to a line by two surfaces of degree s have a semi-stable normal bundle. The author studies the case \(s=3\) and shows that if C is a general non-singular curve of genus 7 and degree 8 on a non-singular cubic surface in \({\mathbb{P}}^ 3\), then the normal bundle of C is stable. He also gives examples of curves of genus 7 and degree 8 with normal bundle in \({\mathbb{P}}^ 3\) non-stable. Finally he considers projectively normal curves on a non-singular cubic surface with \(g\leq d\).