Exhibit A.II

                              WILLIAM BLAIR FUNDS

                        WRITTEN INSTRUMENT AMENDING THE
                              DECLARATION OF TRUST


          The undersigned, being the President of William Blair Funds (the
"Trust"), a Delaware business trust organized pursuant to a Declaration of Trust
dated September 3, 1999, hereby certifies that, in accordance with Section 9.3
of the Declaration of Trust, the following amendment was duly adopted by a
majority of the Trustees of the Trust on April 24, 2001.

          Section 6.3 of the Declaration of Trust is hereby amended by inserting
the following as a new paragraph:

          "(d)  The Trustees may, upon written notice to the affected Holders of
          a particular class of a series, cause the Interests of that class, of
          such Interests of that class as the Trustees shall determine, to be
          exchanged for Interests in another class of that same series; provided
          that (i) the Interests to be exchanged will suffer no reduction in the
          amount payable thereon upon liquidation of the Trust as a result of
          such exchange; (ii) the voting rights of the Interests to be exchanged
          will not be diminished or eliminated by such exchange (except for the
          right to vote on matters affecting only the class to which such
          Interests formerly belonged); and (iii) the Interests to be exchanged
          shall be exchanged for Interests of the other class having the same
          aggregate net asset value at the time of the exchange."

          IN WITNESS WHEREOF, the undersigned has this 24/th/ day of April, 2001
signed these presents.

                                              /s/ Marco Hanig
                                              --------------------------------
                                              Marco Hanig, President