An Observation on F_2 at Low x
  A simple parametrisation of H1 and ZEUS data at HERA is given for the ranges in x and Q^2 of 10^{-4} - 5.10^{-2} and 5 - 250 GeV^2, respectively. This empirical expression is based on a strikingly similar dependence of the average charged particle multiplicity <n> on the centre of mass system energy sqrt{s} in e+e- collisions on the one hand, and the x dependence of the proton structure function F_2 as measured at small x on the other hand. To the best of our knowledge, this similarity has not been noted before. 
A. De Roeck and E. A. De Wolf