  The Gauss map of a conformal minimal immersion of an open Riemann surface $M$
into $\mathbb R^3$ is a meromorphic function on $M$. In this paper, we prove
that the Gauss map assignment, taking a full conformal minimal immersion
$M\to\mathbb R^3$ to its Gauss map, is a Serre fibration. We then determine the
homotopy type of the space of meromorphic functions on $M$ that are the Gauss
map of a complete full conformal minimal immersion, and show that it is the
same as the homotopy type of the space of all continuous maps from $M$ to the
2-sphere. We obtain analogous results for the generalised Gauss map of
conformal minimal immersions $M\to\mathbb R^n$ for arbitrary $n\geq 3$.
