Summary.Single spikes have been recorded by the micro‐electrode technique from the retina of the fully dark adapted decerebrate cat, the aim being to determine the curve of the scotopic dominator with a maximum degree of accuracy in order to find out whether it corresponds with the visual purple (V. P.) distribution of sensitivity as known from work on retinal extracts.The pure on‐elements and some of the on/off‐elements gave a curve slightly narrower than the V. P. curve (e. g. figs. 1 and 2).Some on/off‐elements behaved differently. There were humps in the long and short wave‐lengths in the regions where previously modulators have been noted. In some elements unexpectedly large values were obtained at 0.420 μ (e. g. figs. 3–6).It is concluded that, since the V. P. chromophore would be a complex structure with several conjugated double bonds, it may exist in the retina in states of different probability depending upon the free radicals and the recep