(L) per dL (top) and (M) per dM (bottom). The x-axis ranges are the same; the normalization is n* = 1.0; and three values of 
(-1.5, -1.0, -0.5) are plotted.
The lower version clearly shows how the number of low luminosity galaxies diverges for < -1 because it rises to the left (recall, the lower version gives the number per unit magnitude).
