EXHIBIT 4.6
                                                                     -----------

                        THE DESCARTES SYSTEMS GROUP INC.
                       STOCK OPTION PLAN OPTION AGREEMENT



To:      Arthur Mesher

Date:    SEPTEMBER 30, 2004

Re:      The Descartes Systems Group Inc. Stock Option Plan

Attached hereto is a copy of The Descartes Systems Group Inc. Stock Option Plan
(the "Plan") that has been approved by the Board of Directors of The Descartes
Systems Group Inc. (the "Company").

This is to advise you that you are entitled to participate in the Plan and have
been granted an option to purchase 400,000 common shares (the "Shares") in the
capital of the Company.

         1. The exercise price of the option is Cdn. $1.35 per share.

         2. Your option may be exercised in whole or in part, subject to the
         vesting schedule described in Section 3, at any time or from time to
         time, up to and including, but not after, SEPTEMBER 30, 2011 on which
         date your option, unless terminated earlier on the basis set forth in
         the following sentence or the Plan, shall expire. Subject to the
         foregoing, in the event of the termination of your employment with the
         Company or its Affiliates (as defined in the Plan) other than for cause
         or as a result of resignation, that portion of the option that has not
         vested on the date you receive such notice of termination (the "Notice
         Date") shall expire and terminate on the Notice Date, and that portion
         of the option that has vested on the Notice Date shall expire and
         terminate on the date six months after the Notice Date.

         3. Subject to Sections 2 and 6, your option shall vest in accordance
         with the following vesting schedule:

                       -------------------------- ---------------------
                       VESTING DATE               NO. OF OPTIONS FROM
                                                  GRANT VESTING ON THIS
                                                  VESTING DATE
                       -------------------------- ---------------------
                       March 7, 2006              20,000
                       -------------------------- ---------------------
                       June 7, 2006               20,000
                       -------------------------- ---------------------
                       September 7, 2006          20,000
                       -------------------------- ---------------------
                       December 7, 2006           20,000
                       -------------------------- ---------------------
                       March 7, 2007              20,000
                       -------------------------- ---------------------
                       June 7, 2007               20,000
                       -------------------------- ---------------------
                       September 7, 2007          20,000
                       -------------------------- ---------------------
                       December 7, 2007           20,000
                       -------------------------- ---------------------
                       March 7, 2008              20,000
                       -------------------------- ---------------------
                       June 7, 2008               20,000
                       -------------------------- ---------------------
                       September 7, 2008          20,000
                       -------------------------- ---------------------
                       December 7, 2008           20,000
                       -------------------------- ---------------------
                       March 7, 2009              20,000
                       -------------------------- ---------------------
                       June 7, 2009               20,000
                       -------------------------- ---------------------
                       September 7, 2009          20,000
                       -------------------------- ---------------------
                       December 7, 2009           20,000
                       -------------------------- ---------------------
                       March 7, 2010              20,000
                       -------------------------- ---------------------
                       June 7, 2010               20,000
                       -------------------------- ---------------------
                       September 7, 2010          20,000
                       -------------------------- ---------------------
                       December 7, 2010           20,000
                       -------------------------- ---------------------

         4. The terms and conditions of the Plan are hereby deemed to be
         incorporated into and to form part hereof. If there is a conflict
         between any provision of this Agreement and any provision of the Plan,
         the relevant provision of this Agreement shall prevail.

         5. No share certificates representing the Shares shall be delivered
         until payment of the exercise price for the Shares has been made in
         full.

         6. Notwithstanding any other provision of the Plan or this Agreement,
         if a Change of Control occurs, then all options granted pursuant hereto
         that remain unvested as of the date of any such termination shall
         immediately vest on such date.


         A "Change in Control" shall be deemed to have occurred if (i) any
         person (as defined in the Securities Act (Ontario)) becomes, after the
         date hereof, the owner or "beneficial owner" (as defined in the
         Securities Act (Ontario)), directly or indirectly, of securities of the
         Company representing 50% or more of the combined voting power of the
         Company's then outstanding securities; (ii) during any two year period,
         individuals who at the beginning of such period constitute the Board,
         including for this purpose any additional director whose election was
         approved by a vote of a majority of the directors then in office or who
         were appointed by the directors then in office, cease for any reason to
         constitute a majority thereof; (iii) the Company consummates a merger,
         amalgamation, arrangement or consolidation of the Company or other
         similar transaction with or into another corporation (a
         "Reorganization"), the result of which is that the shareholders of the
         Company at the time of the execution of the agreement relating to the
         Reorganization own less than 50% of the total equity of the corporation
         surviving or resulting from the Reorganization or of a corporation
         owning, directly or indirectly, 100% of the total equity of such
         surviving or resulting corporation; or (iv) the sale in one or a series
         of transactions of all or substantially all of the assets of the
         Company.

         7. Notwithstanding any other provision of the Plan or this Agreement,
         if you are terminated without "Cause" (as defined in your Employment
         Agreement), then any portion of your option that is unvested at the
         date of notice of such termination shall immediately and automatically
         vest as of the date of such notice of termination.

If you desire to accept this option, please so indicate in the space below.
Please note that acceptance does not constitute an exercise of the option.
Options must be exercised in accordance with the terms and conditions of the
Plan by completing and submitting a subscription substantially in the form of
Schedule A annexed to the Plan, accompanied by payment in full of the exercise
price of the option.


                                       THE DESCARTES SYSTEMS GROUP INC.



                                       By: /s/ J. Scott Pagan
                                          -------------------------------------
                                          General Counsel and Corporate
                                          Secretary


I hereby accept the above option and agree to
the terms and the conditions set forth above
including the terms and conditions of the Plan.

/s/ Arthur Mesher
- ------------------------------------
ARTHUR MESHER