  The adsorption of polydisperse ideal polymer chains is shown to be sensitive
to the large N tail of the distribution of chains. If and only if the number of
chains decays more slowly than exponentially then there is an adsorption
transition like that of monodisperse infinite chains. If the number decays
exponentially the adsorption density diverges continuously at a temperature
which is a function of the mean chain length. At low coverages, chains with
repulsive monomer--monomer interactions show the same qualitative behaviour
