Somewhere I remember reading that Marshall said that economics was designed for normal students, and that the best students went into math, physics or philosophy, and that the more practical students went into economics; I think it was in his push for the Economic Tripos at Cambridge. I thought I had read it in Peter Groenewegen's book on Marshall, but I couldn't find it there. Would anyone know where, if anywhere, that discussion might be found? Thanks, Dave Colander