Starting from the exact solution of the mean spherical approximation for the hard core Yukawwa potential, the limit of adhesive hard spheres (i.e. an infinitely strong attractive well with a depth related to the range, which goes to zero, by a power law) is analysed. It is shown that only one choice of the scaling power leads to a model with nontrivial interactions. A critical point is obtained which has spherical model values of the critical exponents, indicating that a singular role is not played by the adhesive-hard-sphere limit.