The expression for the number of inflections 3m(rn - 2) for a curve of the order m was obtained analytically by Plucker, but the theory was first given in a complete form by Hesse in the two papers " Uber die Elimination, u.s.w.," and " Uber die Wendepuncte der Curven dritter Ordnung " (Crelle, t.
P. 337), and in part carried out by Hesse in the memoir " Uber Curven dritter Ordnung " (Crelle, t.
Mobius in the memoir " Ueber die Grundformen der Linien dritter Ordnung " (Abh.
Durbge, Die ebenen Kurven dritter Ordnung (Leipzig, 1871); R.
Schroeter, Die Theorie der ebenen Kurven dritter Ordnung (Leipzig, 1888); H.