Form of Tax Opinion

[Principal  Balanced Fund, Inc.,  Principal  Partners LargeCap Value Fund, Inc.,
Principal  Partners  LargeCap Blend Fund, Inc.,  Principal  LargeCap Stock Index
Fund,  Inc.,  Principal  Partners Equity Growth Fund, Inc.,  Principal  Partners
MidCap  Growth Fund,  Inc.,  Principal  Partners  SmallCap  Growth  Fund,  Inc.,
Principal  Real  Estate  Securities  Fund,  Inc.,  Principal  Bond  Fund,  Inc.,
Principal International Fund, Inc., Principal International SmallCap Fund, Inc.]

June ____, 2005

Board of Directors
Principal Bond Fund, Inc.
680 8th Street
Des Moines, IA 50392-0200

RE:      Acquisition of Principal Bond Fund, Inc.
         By PIF Bond & Mortgage Securities Fund

To the Board of Directors:

PIF Bond & Mortgage Securities Fund, a separate series of Principal Investors
Fund, Inc., a Maryland corporation ("Acquiring"), intends to acquire all of the
assets and assume all of the liabilities of Principal Bond Fund, Inc., a
Maryland corporation ("Target"), in a transaction ("the Reorganization")
described in a Form N-14 Registration Statement, File Number 333-_____, filed
with the United States Securities and Exchange Commission (the "Registration
Statement") on or about March 10, 2005. You have asked for an opinion concerning
the Federal income tax consequences of the proposed transaction.

Continuously since its formation, Acquiring has qualified as a regulated
investment company for purposes of Subchapter M of the United States Internal
Revenue Code of 1986, as amended (the "Code"), and has elected to be taxed as
such.

Target, like Acquiring, has qualified since its inception as a regulated
investment company for purposes of the Code, and has elected to be taxed as
such.

Acquiring and Target are each an open-end management company registered with the
Securities and Exchange Commission and various states.

Acquiring and Target, where applicable, have made the following representations
to the undersigned:

1.       On the effective date of the Reorganization ("the Effective Date"),
         Acquiring will acquire all of the assets of Target solely in exchange
         for Acquiring voting shares ("Acquiring Shares") and the assumption by
         Acquiring of all of Target's liabilities. Target will immediately
         thereafter completely liquidate and dissolve, distributing the
         Acquiring Shares to Target shareholders in retirement of their Target
         shares. Each holder of shares of Target will, as a result of the
         Reorganization, own shares of Acquiring of equal value to the shares of
         Target held by such holder immediately prior to the Reorganization.

2.       The business purpose of the Reorganization will be as set forth in the
         Registration Statement.

3.       The facts relating to the Reorganization, as described in the Agreement
         and Plan of Reorganization, as such document may be amended, ("the
         Plan), and the representations of Acquiring and Target contained in the
         Plan are true, correct and complete.

4.       In the Reorganization, Acquiring will acquire all of the assets of
         Target solely in exchange for Acquiring Shares and Acquiring's
         assumption of all liabilities of the Target.

5.       Acquiring will not assume Target's obligation to pay, and will not pay
         any dividends or distributions on Target's shares.

6.       The fair market value of the Acquiring Shares received by each Target
         shareholder will be approximately equal to the fair market value of the
         Target stock surrendered in the exchange.

7.       A number of full and fractional Acquiring Shares equal in value to the
         aggregate net value of Target's assets transferred to Acquiring, will
         be issued to Target in exchange for such assets.

8.       No cash or property, other than Acquiring Shares, will be directly or
         indirectly transferred to Target or distributed by Target to its
         shareholders pursuant to the Reorganization.

9.       Acquiring will acquire at least 90% of the fair market value of the net
         assets and at least 70% of the fair market value of the gross assets
         held by Target immediately prior to the Reorganization. For purposes of
         this representation, amounts paid by Target to dissenters, amounts used
         by Target to pay its reorganization expenses, amounts paid by Target to
         shareholders who receive cash or other property, and all redemptions
         and distributions (except for regular, normal dividends) made by Target
         immediately preceding the transfer will be included as assets of Target
         held immediately prior to the Reorganization.

10.      Acquiring has no plan or intention to reacquire any of its stock issued
         in the Reorganization, except in connection with its legal obligations
         under Section 22(e) of the Investment Companies Act of 1940.

11.      To the best of Acquiring's and Target's knowledge, there is no plan or
         intention by the  shareholders  of Target who own 5 percent or more of
         Target, and there is no plan or intention on the part of the remaining
         shareholders of Target, to sell, exchange, redeem or otherwise dispose
         of a number of Acquiring  Shares received in the  Reorganization  that
         would reduce Target's shareholders' ownership of Acquiring's shares to
         a number of shares having a value,  as of the Effective  Date, of less
         than 50 percent of the value of all of the formerly outstanding shares
         of Target as of the same date.  For  purposes of this  representation,
         shares of Target exchanged for cash or other property or exchanged for
         cash in lieu of  fractional  shares of  Acquiring  will be  treated as
         outstanding Target shares on the Effective Date.  Moreover,  shares of
         Target and shares of Acquiring  that were held by Target  shareholders
         and that are  otherwise  sold,  redeemed,  or  disposed of prior to or
         subsequent  to the  Reorganization  will be  considered in making this
         representation.

12.      Immediately following the Effective Date, the former shareholders of
         Target will own, in the aggregate, less than 50 percent of the total
         combined voting power of all classes of shares of Acquiring entitled to
         vote, and less than 50 percent of the total value of all classes of
         shares of Acquiring.

13.      After the Reorganization,  Acquiring will use the assets acquired from
         Target  in its  business,  except  that  these  assets  may be sold or
         otherwise  disposed of in the ordinary course of Acquiring's  business
         as an  investment  company  (i.e.  dispositions  resulting  only  from
         investment  decisions  made on the basis of investment  considerations
         arising after and  independent  of the  Reorganization).  Any proceeds
         will be invested in accordance with Acquiring's investment objectives.
         Acquiring has no plan or intention to sell or otherwise dispose of any
         of the assets of Target  acquired  in the  Reorganization,  except for
         dispositions made in the ordinary course of its business.

14.      Following the Reorganization, Acquiring will continue the historic
         business of Target and use a significant portion (i.e., least 34
         percent) of Target's historic business assets in the continuing
         business. Historic business assets are those of Target acquired by it
         in the ordinary course of its business and not in contemplation of, or
         as part of the Reorganization.

15.      The liabilities of Target assumed by Acquiring and any liabilities to
         which the transferred assets of Target are subject were incurred by
         Target in the ordinary course of its business.

16.      Except as provided in the Registration Statement, Target, Acquiring,
         and the shareholders of Target will pay their respective expenses, if
         any, incurred in connection with the Reorganization.

17.      There is no intercorporate indebtedness existing between Acquiring and
         Target that was issued, acquired, or will be settled at discount.

18.      Neither Target nor Acquiring is under the jurisdiction of a court in a
         Title 11 or similar case within the meaning of section 368(a)(3)(A) of
         the Code.

19.      Acquiring and Target each meets the requirements of a regulated
         investment company ("RIC") under section 368(a)(2)(F) of the Code.

20.      The adjusted basis and fair market value of the assets of Target
         transferred to Acquiring will equal or exceed the sum of the
         liabilities to be assumed by Acquiring, plus the amount of the
         liabilities, if any, to which the transferred assets are subject.

21.      None  of  the   compensation,   if  any,   to  be   received   by  any
         shareholder-service  provider  of Target in respect of  services or in
         respect  of  refraining  from  the  performance  of  services  will be
         separate  consideration for, or allocable to, any of his or her Target
         shares.   None  of  the  Acquiring   Shares  to  be  received  by  any
         shareholder-service  provider of Target will be separate consideration
         for or allocable to, any employment  agreement,  consulting agreement,
         covenant not to compete, or similar  arrangement.  Any compensation to
         be paid to any  shareholder-service  provider  of  Target  will be for
         services  actually rendered and will be commensurate with amounts paid
         to third parties  bargaining at arm's length for similar  services and
         has been bargained for independent of the  negotiations  regarding the
         consideration  to be  issued  in  exchange  for  Target  shares in the
         Reorganization.

22.      Target and Acquiring have each elected to be taxed as a RIC under
         section 851 of the Code, and for all of their taxable periods
         (including Target's last short taxable period ending on the Effective
         Date), have qualified for the special tax treatment afforded RICs under
         the Code. After the Reorganization, Acquiring intends to continue to so
         qualify.

23.      There is no plan or intention for Acquiring (the issuing corporation as
         defined in Treasury Regulation section 1.368-1(b)) or any person
         related (as defined in section 1.368-1(e)(3)) to Acquiring, to acquire
         during the five-year period beginning on the date of the
         Reorganization, with consideration other than Acquiring stock,
         Acquiring stock furnished in exchange for a proprietary interest in
         Target in the Reorganization, either directly or through any
         transaction, agreement, or arrangement with any other person.

24.      During  the  five-year  period  ending  on the  Effective  Date of the
         Reorganization:  (i)  neither  Acquiring,  nor any person  related (as
         defined in section  1.368-1(e)(3))  to  Acquiring,  will have acquired
         Target stock with  consideration  other than  Acquiring  Shares,  (ii)
         neither   Target  nor  any  person  related  (as  defined  in  section
         1.368-1(e)(3))  without  regard  to  section  1.368-1(e)(3)(i)(A))  to
         Target,  will have acquired Target stock with consideration other than
         Acquiring Shares or Target stock, and (iii) no distributions will have
         been made with respect to Target stock (other than  ordinary,  normal,
         regular  dividend  distributions  made  pursuant to Target's  historic
         dividend paying practice), either directly or through any transaction,
         agreement,  or arrangement with any other person,  except for (a) cash
         paid to dissenters,  and (b) distributions  described in Code sections
         852 and 4982,  as required for  Target's tax  treatment as a RIC or to
         avoid Federal excise tax.

25.      The aggregate value of the acquisitions, redemptions, and distributions
         described in the two immediately preceding paragraphs will not exceed
         50 percent of the value (without giving effect to the acquisitions,
         redemptions, and distributions) of the proprietary interest in Target
         on the Effective Date.

In reliance on the information provided in the Registration Statement, I am of
the opinion that:

1.       The acquisition of all of the assets and liabilities of Target by
         Acquiring solely in exchange for Acquiring Shares, followed by
         distribution of those Acquiring Shares to shareholders of Target in
         complete liquidation of Target, will constitute a reorganization within
         the meaning of section 368(a)(1) of the Code. Each of Acquiring and
         Target will be a "party to a reorganization" within the meaning of
         section 368(b) of the Code.

2.       Shareholders of Target will recognize no gain or loss as a consequence
         of the surrender of their shares of Target solely in exchange for
         Acquiring Shares pursuant to the Reorganization. (Code Section 354).

3.       The aggregate tax basis and holding period of Acquiring Shares received
         solely in exchange for shares of Target will be the same as the
         aggregate tax basis and the holding period of the shares of Target
         exchanged therefor provided such shares were held as a capital asset on
         the Effective Date. (Code Sections 358 and 1223(1))

4.       Target will recognize no gain or loss on the transfer of all of its
         assets to Acquiring solely in exchange for Acquiring Shares and the
         assumption of all of Target's liabilities by Acquiring, and Target will
         not recognize gain or loss upon the distribution to its shareholders of
         all of the Acquiring Shares in complete liquidation of Target. (Code
         Section 361 and 357(a).

5.       The tax basis of the assets of Target in the hands of Acquiring will be
         the same as the tax basis of those assets in the hands of Target
         immediately prior to the Effective Date. (Code Section 362(b)).

6.       The holding period of the assets of Target received by Acquiring will
         include the period during which such assets were held by Target. (Code
         Section 1223(2)).

7.       No gain or loss will be recognized by Acquiring upon the receipt of
         Target's assets solely in exchange for the Acquiring Shares and the
         assumption by Acquiring of all liabilities of Target. (Code Section
         1032).

The foregoing opinions are based on the Code, Treasury Regulations issued
thereunder, published administrative, interpretations thereof and judicial
decisions with respect thereto, all as of the date hereof (collectively the "Tax
Law"), including the requirements of section 10.37 of Circular 230. No assurance
can be given that the Tax Laws will not change.

I hereby consent to the use of this letter as an Exhibit to, and reference to it
in, the Registration Statement.

Sincerely yours,


Carolyn Kolks
Assistant Tax Counsel to Target