  A quaternion order O over a Dedekind domain R is Bass if every R-superorder
is Gorenstein, and O is basic if it contains an integrally closed quadratic
R-order. In this article, we show that these conditions are equivalent in local
and global settings: a quaternion order is Bass if and only if it is basic. In
particular, we show that the property of being basic is a local property of a
quaternion order.
