  We investigate the consequences of an increase in the envelope helium
abundance of pre-helium flash red giants in globular clusters. Comparing
predictions with the CM diagrams of a few crucial GC, one finds no evidence for
a substantial increase in the surface helium content of HB members of these
clusters, at least for objects in the RR Lyrae region or close to it. The
possibility that the most peculiar giants belong to the asymptotic giant branch
is discussed. The consequences of a delay in the helium flash are briefly
examined.
