  This note (which makes no claim to novelty) presents a proof of the separable
rational connectedness of smooth cubic hypersurfaces, in any characteristic, by
showing how to explicitly construct very free curves (of degree 3) on them.
  -----
  Cette note (qui ne pr\'etend pas \`a l'originalit\'e) d\'emontre la
s\'eparable rationnelle connexit\'e des hypersurfaces cubiques lisses, en toute
caract\'eristique, en construisant explicitement des courbes tr\`es libres (de
degr\'e 3) trac\'ees dessus.
