EXHIBIT 10(SS)
                           BANK OF BOSTON CORPORATION

                               THE BOSTON BANCORP

                                  March 7, 1996

Bank of Boston Corporation
The Boston Bancorp

Gentlemen:

         This Letter Agreement amends certain provisions of the Agreement and
Plan of Reorganization by and between Bank of Boston Corporation ("Bank of
Boston") and The Boston Bancorp ("Bancorp") dated as of October 10, 1995 (the
"Merger Agreement") and Schedule 1 attached thereto ("Schedule 1"). Bank of
Boston and Bancorp have agreed to modify certain terms of the Merger Agreement
and Schedule 1 as follows:

A.       Amendments to the Merger Agreement

         1. The definition of "Adjusted Net Worth" in Article 1 is hereby
amended in subpart (iv) by substituting the words "Thrift Fund" for "Central
Fund."

         2. The term and definition of "Central Fund" contained in Article 1 is
hereby deleted in its entirety.

         3. The definition of "Material Adverse Effect" in Article 1 is hereby
amended by inserting the following phrase immediately at the end thereof:

                 "; provided further that the agreement of the parties
                 to use zero as the minimum value for the variable
                 component of the formula for determining the
                 Conversion Number shall not prejudice the rights of
                 either party in determining whether a Material
                 Adverse Effect has occurred for purposes of this
                 Agreement."

         4. Article 1 is hereby amended by adding the following definition after
the definition of "Termination Date," on page 9:

                 "Thrift Fund" shall mean the Thrift Institution Fund
                 for Economic Development."

         5. Section 2.09(a) is hereby amended by deleting paragraph (i) in its
entirety and inserting the following new paragraph (i) in place thereof:

                 "(i) the sum of (A) $40,640,806.00 and (B) an amount
                 equal to the greater of (1) zero, or (2) the sum of
                 (a) the Adjusted Net Worth as of the close of
                 business on the Measurement Date, (b) the product of
                 $40,000.00 and the number of days after the
                 Measurement Date to and including the Closing Date,
                 and (c) the aggregate exercise price of all options
                 to purchase Seller Common Stock outstanding at the
                 close of business on the Measurement Date, by"

         6. Section 3.04 is hereby amended by substituting the words "Thrift
Fund" for "Central Fund" in line 6.

         7. Section 4.04 is hereby amended by substituting the words "Thrift
Fund" for "Central Fund" in line 3.
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         8. Section 8.01 is hereby amended by renumbering paragraphs (d) and (e)
as paragraphs (e) and (f) respectively and inserting the following new paragraph
(d) therein:

                 "(d) by Buyer if the Adjusted Net Worth of Seller
                 shall at any time after the date hereof equal an
                 amount less than zero;"

B.       Amendment to Schedule 1

         Delete item 2 following the discussion of the mandatory pre-closing
         transactions on Page 2 and replace with the following:

                 "Liquidate all outstanding advances previously made
                 to the Thrift Fund."

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         Except as expressly set forth herein, all terms and conditions of the
Merger Agreement and Schedule 1 are hereby ratified and confirmed and shall
remain in full force and effect and each party hereto expressly affirms all of
its obligations under the Merger Agreement and Schedule 1. Please acknowledge
your agreement with the foregoing amendments by signing the enclosed copy of
this letter in the places provided below.

                                               Very truly yours,

                                               BANK OF BOSTON CORPORATION

                                               By: _____________________________

                                               THE BOSTON BANCORP

                                               By: _____________________________