  The Horizontal Branch (HB) morphology in the color -- magnitude diagram of
the Galactic globular clusters depends on many factors, and it is now firmly
established that the so-called Second Parameter is not just the cluster age as
claimed for several years. As a part of a wider program devoted to the search
for the physical processes driving the Horizontal Branch Morphology, we
re-address here the problem of the extension of blue HB tails by introducing a
new quantitative observable, B2/B+R+V where B2={Number of HB stars with
(B-V)_0<-0.02}. We demonstrate that the environmental conditions within a
cluster clearly affect its HB morphology, in the sense that, in general, the
higher the cluster central density the higher is the relative number of stars
populating the most blue region of its HB.
