A, B, Frequency histograms of the lengths of rendered postsynaptic filaments at the synapses rendered first (A) and second (B). C-E, Cumulative frequency curves for the diameters of short (C), medium (D), and long filaments (E) at the two synapses rendered. Vertical lines indicate the diameter at which 50% of the filaments at the synapses rendered first (broken line) and second (solid line) are accounted for.