  We discuss the situation where attractive and repulsive portions of the
inter-particle potential both contribute significantly to glass formation. We
introduce the square-well potential as prototypical model for this situation,
and {\it reject} the Baxter as a useful model for comparison to experiment on
glasses, based on our treatment within mode coupling theory. We present
explicit results for various well-widths, and show that, for narrow wells,
there is a useful analytical formula that would be suitable for experimentalist
working in the field of colloidal science. We raise the question as to whether,
in a more exact treatment, the sticky sphere limit might have an infinite glass
transition temperature, or a high but finite one.
