Hello,
      I have heard told by some of our pediatricians at our hospital that the
only real need to introducing solids at any point is to increase the iron in
the diet of the baby because by 6 mo to 1 year the iron stores the baby is
born with in the liver, bone marrow and red blood cells starts to dwindle.
The iron provided by the breastmilk or formula simply replaces iron that is
lost on a daily basis or used for building more red blood cells.  I suppose if
the mother is not anemic and the baby took occassional iron containing finger
foods they could thrive up to 2 yo on mainly breastmilk.
     In Mothering magazine they had an article in a recent volume that
discussed highly allergic children and nursing them exclusively up to 2 yrs
old and slowly introducing finger food to delay or avoid any sensitivity to
allergic proteins etc.  These children seemed to thrive and were not anemic or
so not reported.
     Myself, my kids were following our every bite at 6 months of age.  I
don't know if I could have held them off any longer.  Interesting antedotal
experience.

                                                      Cynthia S. Marske DO