Analysis shows that the initial curvature of the distribution curve is always smaller for a polydisperse system than for a monodisperse system than for a monodisperse system. From this information and a knowledge of the position of the asymptote, it appears that the curve for a polydisperse case lies below the curve for a monodisperse case. The asymptotic behavior of the angular distribution function is shown to be unmodified by branching. These and other considerations indicate that the precise determination of the whole distribution curve is highly desirable, since it can give useful information about branching or polydispersity provided that only 1 of these 2 effects is present. If both effects are present, the asymptote only permits the determination of the size of unbranched molecules with molecular weight Mw.