Radius distribution of all HII regions at three different redshifts for the three simulations for the 50 Mpc/h box. This time, we dissociate the distribution into the different counterparts of the type of HII region considered. We compare the difference in the radius distribution according to both ionization thresholds of x ≥ 0.5 and x ≥ 0.9 for the detection of the HII region with the FOF procedure. The colors stand for the new HII regions (blue), the expanding regions (red), the regions that will recombine (yellow), and the regions resulting from mergers (green). In addition we represent the volume of one single cell by the vertical black line.