2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/107526In this paper we study degenerations of scrolls to union of planes, a problem already considered by G. Zappa in 1940-50. We prove, using techniques different from the ones of Zappa, a degeneration result to union of planes with the mildest possible singularities, for linearly normal scrolls of genus $g$ and of degree $d$ larger than $2g+4$ in $\Pp^{d-2g+1}$. We also study properties of components of the Hilbert scheme parametrizing scrolls. Finally we review Zappa's original approach.Latex2e, 26 pages, 15 figures. submitted preprint. v.2: some misprints are correctedAlgebraic Geometry14J26, 14D06, 14N20; (Secondary) 14H60, 14N10text