OFFICERS' POWER OF ATTORNEY

City of Minneapolis

State of Minnesota

         Each of the  undersigned,  as  officers of the below  listed  open-end,
diversified   investment  companies  that  previously  have  filed  registration
statements and amendments thereto pursuant to the requirements of the Securities
Act of 1933 and the  Investment  Company  Act of 1940  with the  Securities  and
Exchange Commission:

                                                     1940 Act
                                                     Reg. Number

         Growth Trust                                811-07395
         Growth and Income Trust                     811-07393
         Income Trust                                811-07307
         Tax-Free Income Trust                       811-07397
         World Trust                                 811-07399

hereby constitutes and appoints the other as his  attorney-in-fact and agent, to
sign for him in his name, place and stead any and all further amendments to said
registration   statements  filed  pursuant  to  said  Acts  and  any  rules  and
regulations  thereunder,  and to file such amendments with all exhibits  thereto
and other  documents in connection  therewith  with the  Securities and Exchange
Commission,  granting to either of them the full power and  authority  to do and
perform  each and every act  required  and  necessary  to be done in  connection
therewith.

         Dated the 13th day of January, 2000.


/s/  Arne H. Carlson                                 /s/  Leslie L. Ogg
     Arne H. Carlson                                      Leslie L. Ogg

/s/  John R. Thomas                                  /s/  Peter J. Anderson
     John R. Thomas                                       Peter J. Anderson

/s/  Frederick C. Quirsfeld                          /s/  John M. Knight
     Frederick C. Quirsfeld                               John M. Knight