SUPPLEMENT TO THE CURRENTLY EFFECTIVE PROSPECTUSES:

                                 -----------------

Money Market Portfolio                       Tax-Exempt Portfolio
  Davidson Cash Equivalent Shares              Davidson Cash Equivalent Shares
  Davidson Cash Equivalent Plus Shares
Government & Agency Securities Portfolio
  Davidson Cash Equivalent Shares
  Davidson Cash Equivalent Plus Shares

The following information supplements the disclosure in the "Other Policies"
section of each portfolio's prospectuses:

The portfolio may also post on the Web site, on a more frequent basis, a
percentage breakdown of the holdings of the portfolio by type of security.

The following information replaces similar disclosure in the "Policies You
Should Know About -- Transaction Processing" section of each portfolio's
prospectuses:

Transaction Processing. Orders for the purchase of shares by wire transfer will
normally be effective at the share price next computed after receipt of the wire
transfer of the amount to be invested. If a wire transfer purchase order is
received in good form prior to 4:00 p.m. Eastern time (3:00 p.m. Eastern time
for Tax-Exempt Portfolio), it will normally receive the dividend for that day.

Investments by check will be effective on the business day following receipt and
will earn dividends the following business day.

Please contact your financial advisor for wire instructions and purchase orders.

When selling shares, shareholders generally receive dividends up to, but not
including, the business day following the day on which the shares were sold. If
the portfolio receives a sell request before 4:00 p.m. Eastern time (3:00 p.m.
Eastern time for Tax-Exempt Portfolio) and the request calls for proceeds to be
sent out by wire, the proceeds will normally be wired on the same day. However,
the shares sold will not earn that day's dividend.

As noted elsewhere in the prospectus, proceeds of a redemption may be delayed.
The ability to receive "same day" wire redemption proceeds can be affected by a
variety of circumstances including the time that the request is made, the level
of redemption requests and purchase orders and general market conditions.
Requests for same day wire that are received earlier in the day will be given
priority over requests received later in the day in the event that it is
necessary to limit the amount of same day wire redemptions.


March 31, 2008
DADP-3600
<PAGE>

The following information replaces similar disclosure under the "Policies You
Should Know About -- How each portfolio calculates share price" section of each
portfolio's prospectuses:

The portfolio is open for business each day the New York Stock Exchange is open.
Normally, the portfolio calculates its share price once every business day as of
the close of regular trading on the Exchange (typically 4:00 p.m. Eastern time,
but sometimes earlier, as in the case of scheduled half-day trading or
unscheduled suspensions of trading). In the event of scheduled partial day
trading or unscheduled suspensions of trading on the Exchange, the calculation
of share price shall be as of the close of trading on the Exchange and the
latest time for receipt of wire purchase transactions entitled to receive same
day dividend treatment and for receipt of redemption orders for same day wire
transfer of proceeds will be the earlier of (a) the times set forth in the
prospectus or (b) the early closing time of the Exchange. The portfolio seeks to
maintain a stable $1.00 share price.

The portfolio may, but is not required to, accept certain types of purchase and
redemption orders (not including exchanges) on days that the Exchange is closed,
or beyond an Exchange early closing time (referred to as a "Limited Trading
Period") if: (a) the Federal Reserve system is open, (b) the primary trading
markets for the portfolio's portfolio instruments are open and (c) the Advisor
believes there will be adequate liquidity in the short-term markets. During any
such Limited Trading Period, the portfolio will only accept purchase orders by
wire and telephone redemption orders with proceeds to be sent by wire, ACH or
check and will not accept orders by any other means. (Automated Telephone Line
orders are not permitted.) If redemption proceeds are requested by ACH or check,
the transmission of the ACH payment or the mailing of the check, as the case may
be, will be delayed by at least one business day in comparison to normal trading
periods. Orders submitted by other means will be processed on the next day that
the Exchange is open. The calculation of share price will be at the time set
forth in the prospectus for normal trading days. Orders must be submitted by the
cut-off times for receipt of wire purchases entitled to that day's dividend and
for receipt of telephone redemption orders for same day wire transfer, which
will be the earlier of: (a) the times set forth in the prospectus for normal
trading days or (b) such earlier times that the portfolio determines based on
the criteria described above. If redemption proceeds are requested by ACH or
check, orders must be received prior to the calculation of share price. Please
contact your financial advisor for additional information about whether the
portfolio will be open for business on a particular day. Information concerning
the intention of a portfolio to be open for a Limited Trading Period will be
available at least one business day prior to the applicable day that the
Exchange is closed or is closing early in the case of scheduled closings and as
soon as practical in the case of unscheduled closings.


March 31, 2008
DADP-3600

               Please Retain This Supplement for Future Reference