If many micelles adsorb onto the same polymer molecule then they are said to form a necklace. A minimal model of such a necklace is proposed and shown to be almost equivalent to a one-dimensional fluid with nearest-neighbour interactions. The thermodynamic functions of this fluid are obtained and then used to predict the change in the critical micellar concentration of the surfactant in the presence of the polymer. If the amount of polymer is not too large there are two critical micellar concentrations, one for micelles in necklaces and one for free micelles.