EXHIBIT 3.22











                                    BYLAWS

                                      OF

                    MAXUM HEALTH SERVICES OF DALLAS, INC.



                              September 29, 1995






                              TABLE OF CONTENTS






                                                                          Page



PREAMBLE                                                                    1

ARTICLE ONE: OFFICES

        1.01 Registered Office and Agent..................................  1
        1.02 Other Offices................................................  1

ARTICLE TWO: SHAREHOLDERS

        2.01 Annual Meetings..............................................  1
        2.02 Special Meetings.............................................  1
        2.03 Place of Meetings............................................  2
        2.04 Notice.......................................................  2
        2.05 Voting List..................................................  2
        2.06 Voting of Shares.............................................  2
        2.07 Quorum; Withdrawal of Quorum.................................  3
        2.08 Majority Vote................................................  3
        2.09 Method of Voting; Proxies....................................  3
        2.10 Closing of Transfer Records; Record Date.....................  4
        2.11 Officers Duties at Meeting...................................  4
        2.12 Action Without Meeting.......................................  5

ARTICLE THREE: DIRECTORS

        3.01 Management...................................................  5
        3.02 Number; Election; Term; Qualification........................  5
        3.03 Change in Number.............................................  5
        3.04 Removal......................................................  6
        3.05 Vacancies....................................................  6
        3.06 Place of Meetings............................................  6
        3.07 First Meeting................................................  7
        3.08 Regular Meetings.............................................  7
        3.09 Special Meetings; Notice.....................................  7
        3.10 Quorum; Majority Vote........................................  7
        3.11 Procedure; Minutes...........................................  7
        3.12 Presumption of Assent........................................  7
        3.13 Compensation.................................................  8
        3.14 Action Without Meeting.......................................  8



                                     (i)




ARTICLE FOUR: COMMITTEES

        4.01 Designation..................................................  8
        4.02 Number; Qualification; Term..................................  8
        4.03 Authority....................................................  8
        4.04 Committee Changes............................................ 10
        4.05 Regular Meetings............................................. 10
        4.06 Special Meetings............................................. 10
        4.07 Quorum; Majority Vote........................................ 10
        4.08 Minutes...................................................... 10
        4.09 Compensation................................................. 10
        4.10 Responsibility............................................... 10

ARTICLE FIVE: GENERAL PROVISIONS RELATING TO MEETINGS

        5.01 Notice....................................................... 11
        5.02 Waiver of Notice............................................. 11
        5.03 Telephone and Similar Meetings............................... 11

ARTICLE SIX: OFFICERS AND OTHER AGENTS

        6.01 Number; Titles; Election; Term; Qualification................ 11
        6.02 Removal...................................................... 12
        6.03 Vacancies.................................................... 12
        6.04 Authority.................................................... 12
        6.05 Compensation................................................. 12
        6.06 Chairman of the Board........................................ 12
        6.07 President.................................................... 12
        6.08 Vice Presidents.............................................. 13
        6.09 Treasurer.................................................... 13
        6.10 Assistant Treasurers......................................... 13
        6.11 Secretary.................................................... 14
        6.12 Assistant Secretaries........................................ 14

ARTICLE SEVEN: CERTIFICATES AND SHAREHOLDERS

        7.01 Certificated and Uncertificated Shares....................... 14
        7.02 Certificates for Certificated Shares......................... 14
        7.03 Issuance..................................................... 15
        7.04 Consideration for Shares..................................... 15
        7.05 Lost, Stolen, or Destroyed Certificates...................... 15
        7.06 Transfer of Shares........................................... 16
        7.07 Registered Shareholders...................................... 17

                                     (ii)




        7.08 Legends...................................................... 17
        7.09 Regulations.................................................. 17

ARTICLE EIGHT: MISCELLANEOUS PROVISIONS

        8.01 Dividends.................................................... 17
        8.02 Books and Records............................................ 17
        8.03 Fiscal Year.................................................. 17
        8.04 Seal......................................................... 18
        8.05 Attestation by the Secretary................................. 18
        8.06 Resignation.................................................. 18
        8.07 Securities of Other Corporations............................. 18
        8.08 Amendment of Bylaws.......................................... 18
        8.09 Invalid Provisions........................................... 18
        8.10 Headings; Table of Contents.................................. 18



                                    (iii)





                                     BYLAWS

                                       OF

                      MAXUM HEALTH SERVICES OF DALLAS, INC.

                               A Texas Corporation


                                    PREAMBLE

        These bylaws are subject to, and governed by, the Texas Business
Corporation Act and the articles of incorporation of Maxum Health Services of
Dallas, Inc. (the "Corporation"). In the event of a direct conflict between the
provisions of these bylaws and the mandatory provisions of the Texas Business
Corporation Act or the provisions of the articles of incorporation of the
Corporation, such provisions of the Texas Business Corporation Act or the
articles of incorporation of the Corporation, as the case may be, will be
controlling.


                              ARTICLE ONE: OFFICES


        1.01 Registered Office and Agent. The registered office and registered
agent of the Corporation shall be as designated from time to time by the
appropriate filing by the Corporation in the office of the Secretary of State of
Texas.

        1.02 Other Offices. The Corporation may also have offices at such other
places, both within and without the State of Texas, as the board of directors
may from time to time determine or the business of the Corporation may require.


                            ARTICLE TWO: SHAREHOLDERS


        2.01 Annual Meetings. An annual meeting of shareholders of the
Corporation shall be held during each calendar year on such date and at such
time as shall be designated from time to time by the board of directors and
stated in the notice of the meeting, if not a legal holiday in the place where
the meeting is to be held, and, if a legal holiday in such place, then on the
next business day following, at the time specified in the notice of the meeting.
At such meeting, the shareholders shall elect directors and transact such other
business as may properly be brought before the meeting.

        2.02 Special Meetings. A special meeting of the shareholders may be
called at any time by the president, the board of directors, or the holders of
not less than ten percent of all shares entitled to vote at such meeting. Only
business within the purpose





or purposes described in the notice of special meeting may be conducted at such
special meeting.

        2.03 Place of Meetings. The annual meeting of shareholders may be held
at any place within or without the State of Texas designated by the board of
directors. Special meetings of shareholders may be held at any place within or
without the State of Texas designated by the person or persons calling such
special meeting as provided in Section 2.02 above. Meetings of shareholders
shall be held at the principal office of the Corporation unless another place is
designated for meetings in the manner provided herein.

        2.04 Notice. Except as otherwise provided by law, written or printed
notice stating the place, day, and hour of each meeting of the shareholders and,
in case of a special meeting, the purpose or purposes for which the meeting is
called, shall be delivered not less than ten nor more than sixty days before the
date of the meeting by or at the direction of the president, the secretary, or
the person calling the meeting, to each shareholder of record entitled to vote
at such meeting.

        2.05 Voting List. At least ten days before each meeting of shareholders,
the secretary shall prepare a complete list of shareholders entitled to vote at
such meeting, arranged in alphabetical order, including the address of each
shareholder and the number of voting shares held by each shareholder. For a
period of ten days prior to such meeting, such list shall be kept on file at the
registered office or principal place of business of the Corporation and shall be
subject to inspection by any shareholder during usual business hours. Such list
shall be produced at such meeting, and at all times during such meeting shall be
subject to inspection by any shareholder. The original share transfer records
shall be prima facie evidence as to who are the shareholders entitled to examine
such list.

        2.06 Voting of Shares. Treasury shares, shares of the Corporation's own
stock owned by another corporation the majority of the voting stock of which is
owned or controlled by the Corporation, and shares of the Corporation's own
stock held by the Corporation in a fiduciary capacity shall not be shares
entitled to vote or to be counted in determining the total number of outstanding
shares. Shares standing in the name of another domestic or foreign corporation
of any type or kind may be voted by such officer, agent, or proxy as the bylaws
of such corporation may authorize or, in the absence of such authorization, as
the board of directors of such corporation may determine. Shares held by an
administrator, executor, guardian, or conservator may be voted by him, either in
person or by proxy, without transfer of such shares into his name so long as
such shares form a part of the estate served by him and are in the possession of
such estate. Shares held by a trustee may be voted by him, either in person or
by proxy, only after the shares have been transferred into his name as trustee.
Shares standing in the name of a receiver may be voted by such receiver, and
shares held by or under the control of a receiver may be voted by such receiver
without transfer of such shares into his name if authority to do so is contained
in the court order by which such receiver was appointed. A shareholder


                                        2



whose shares are pledged shall be entitled to vote such shares until they have
been transferred into the name of the pledgee, and thereafter, the pledgee shall
be entitled to vote such shares.

        2.07 Quorum; Withdrawal of Quorum. A quorum shall be present at a
meeting of shareholders if the holders of a majority of the shares entitled to
vote are represented at the meeting in person or by proxy, except as otherwise
provided by law or the articles of incorporation. If a quorum shall not be
present at any meeting of shareholders, the shareholders represented in person
or by proxy at such meeting may adjourn the meeting until such time and to such
place as may be determined by a vote of the holders of a majority of the shares
represented in person or by proxy at that meeting. Once a quorum is present at a
meeting of shareholders, the shareholders represented in person or by proxy at
the meeting may conduct such business as may be properly brought before the
meeting until it is adjourned, and the subsequent withdrawal from the meeting of
any shareholder or the refusal of any shareholder represented in person or by
proxy to vote shall not affect the presence of a quorum at the meeting.

        2.08 Majority Vote. Directors of the Corporation shall be elected by a
majority of the votes cast by the holders of shares entitled to vote in the
election of directors of the Corporation, represented in person or by proxy at a
meeting of shareholders at which a quorum is present. Except as otherwise
provided by law, the articles of incorporation, or these bylaws, with respect to
any matter, the affirmative vote of the holders of a majority of the
Corporation's shares entitled to vote on that matter and represented in person
or by proxy at a meeting at which a quorum is present shall be the act of the
shareholders.

        2.09 Method of Voting; Proxies. Every shareholder of record shall be
entitled at every meeting of shareholders to one vote on each matter submitted
to a vote, for every share standing in his name on the original share transfer
records of the Corporation except to the extent that the voting rights of the
shares of any class or classes are increased, limited, or denied by the articles
of incorporation. Such share transfer records shall be prima facie evidence as
to the identity of shareholders entitled to vote. At any meeting of
shareholders, every shareholder having the right to vote may vote either in
person or by a proxy executed in writing by the shareholder or by his duly
authorized attorney-in-fact. Each such proxy shall be filed with the secretary
of the Corporation before, or at the time of, the meeting. No proxy shall be
valid after eleven months from the date of its execution, unless otherwise
provided in the proxy. If no date is stated on a proxy, such proxy shall be
presumed to have been executed on the date of the meeting at which it is to be
voted. Each proxy shall be revocable unless the proxy form conspicuously states
that the proxy is irrevocable and the proxy is coupled with an interest.

        2.10 Closing of Transfer Records; Record Date. For the purpose of
determining shareholders entitled to notice of, or to vote at, any meeting of
shareholders or any


                                        3



adjournment thereof, or entitled to receive a distribution (other than a
distribution involving a purchase or redemption by the Corporation of any of its
own shares) or a share dividend, or in order to make a determination of
shareholders for any other proper purpose (other than determining shareholders
entitled to consent to action by shareholders proposed to be taken without a
meeting of shareholders), the board of directors may provide that the share
transfer records of the Corporation shall be closed for a stated period but not
to exceed in any event sixty days. If the share transfer records are closed for
the purpose of determining shareholders entitled to notice of, or to vote at, a
meeting of shareholders, such records shall be closed for at least ten days
immediately preceding such meeting. In lieu of closing the share transfer
records, the board of directors may fix in advance a date as the record date for
any such determination of shareholders, such date in any case to be not more
than sixty days and, in case of a meeting of shareholders, not less than ten
days prior to the date on which the particular action requiring such
determination of shareholders is to be taken. If the share transfer records are
not closed and if no record date is fixed for the determination of shareholders
entitled to notice of, or to vote at, a meeting of shareholders or entitled to
receive a distribution (other than a distribution involving a purchase or
redemption by the Corporation of any of its own shares) or a share dividend, the
date on which the notice of the meeting is mailed or the date on which the
resolution of the board of directors declaring such distribution or share
dividend is adopted, as the case may be, shall be the record date for such
determination of shareholders. When a determination of shareholders entitled to
vote at any meeting of shareholders has been made as provided in this Section
2.10, such determination shall apply to any adjournment thereof except where the
determination has been made through the closing of the share transfer records
and the stated period of closing has expired.

        2.11 Officers Duties at Meetings. The president shall preside at, and
the secretary shall prepare minutes of, each meeting of shareholders, and in the
absence of either such officer, his duties shall be performed by some person or
persons elected by the vote of the holders of a majority of the outstanding
shares entitled to vote, present in person or represented by proxy.

        2.12 Action Without Meeting. Any action which may be taken, or which is
required by law or the articles of incorporation or bylaws of the Corporation to
be taken, at any annual or special meeting of shareholders, may be taken without
a meeting, without prior notice, and without a vote, if a consent or consents in
writing, setting forth the action so taken, shall have been signed by the holder
or holders of shares having not less than the minimum number of votes that would
be necessary to take such action at a meeting at which the holders of all shares
entitled to vote on the action were present and voted. The signed consent or
consents of shareholders shall be placed in the minute books of the Corporation.
The record date for the purpose of determining shareholders entitled to consent
to any action pursuant to this Section 2.12 shall be determined in accordance
with Article 2.26.C of the Texas Business Corporation Act.


                                        4

                            ARTICLE THREE: DIRECTORS


        3.01 Management. The powers of the Corporation shall be exercised by or
under the authority of, and the business and affairs of the Corporation shall be
managed under the direction of, the board of directors.

        3.02 Number; Election; Term; Qualification. The number of directors
which shall constitute the board of directors shall be not less than one. The
first board of directors shall consist of the number of directors named in the
articles of incorporation. Thereafter, the number of directors which shall
constitute the entire board of directors shall be determined by resolution of
the board of directors at any meeting thereof or by the shareholders at any
meeting thereof, but shall never be less than one. At each annual meeting of
shareholders, directors shall be elected to hold office until the next annual
meeting of shareholders and until their successors are elected and qualified. No
director need be a shareholder, a resident of the State of Texas, or a citizen
of the United States.

        3.03 Changes in Number. No decrease in the number of directors
constituting the entire board of directors shall have the effect of shortening
the term of any incumbent director. Any directorship to be filled by reason of
an increase in the number of directors may be filled by (i) the shareholders at
any annual or special meeting of shareholders called for that purpose or (ii)
the board of directors for a term of office continuing only until the next
election of one or more directors by the shareholders; provided that the board
of directors may not fill more than two such directorships during the period
between any two successive annual meetings of shareholders. Notwithstanding the
foregoing, whenever the holders of any class or series of shares are entitled to
elect one or more directors by the provisions of the articles of incorporation,
any newly created directorship(s) of such class or series to be filled by reason
of an increase in the number of such directors may be filled by the affirmative
vote of a majority of the directors elected by such class or series then in
office or by a sole remaining director so elected or by the vote of the holders
of the outstanding shares of such class or series, and such directorship(s)
shall not in any case be filled by the vote of the remaining directors or by the
holders of the outstanding shares of the Corporation as a whole unless otherwise
provided in the articles of incorporation.

        3.04 Removal. At any meeting of shareholders called expressly for that
purpose, any director or the entire board of directors may be removed, with or
without cause, by a vote of the holders of a majority of the shares then
entitled to vote on the election of directors. Notwithstanding the foregoing,
whenever the holders of any class or series of shares are entitled to elect one
or more directors by the provisions of the articles of incorporation, only the
holders of shares of that class or series shall be entitled to vote



                                        5





for or against the removal of any director elected by the holders of shares of
that class or series.

        3.05 Vacancies. Any vacancy occurring in the board of directors may be
filled by (i) the shareholders at any annual or special meeting of shareholders
called for that purpose or (ii) the affirmative vote of a majority of the
remaining directors though less than a quorum of the board of directors. A
director elected to fill a vacancy shall be elected to serve for the unexpired
term of his predecessor in office. Notwithstanding the foregoing, whenever the
holders of any class or series of shares are entitled to elect one or more
directors by the provisions of the articles of incorporation, any vacancies in
such directorship(s) may be filled by the affirmative vote of a majority of the
directors elected by such class or series then in office or by a sole remaining
director so elected or by the vote of the holders of the outstanding shares of
such class or series, and such directorship(s) shall not in any case be filled
by the vote of the remaining directors or the holders of the outstanding shares
of the Corporation as a whole unless otherwise provided in the articles of
incorporation.

        3.06 Place of Meetings. The board of directors may hold its meetings in
such place or places within or without the State of Texas as the board of
directors may from time to time determine.

        3.07 First Meeting. Each newly elected board of directors may hold its
first meeting for the purpose of organization and the transaction of business,
if a quorum is present, immediately after and at the same place as the annual
meeting of shareholders, and notice of such meeting shall not be necessary.

        3.08 Regular Meetings. Regular meetings of the board of directors may be
held without notice at such times and places as may be designated from time to
time by resolution of the board of directors and communicated to all directors.

        3.09 Special Meetings; Notice. Special meetings of the board of
directors shall be held whenever called by the president or by any director. The
person calling any special meeting shall cause notice of such special meeting,
including therein the time and place of such special meeting, to be given to
each director at least two days before such special meeting. Neither the
business to be transacted at, nor the purpose of, any special meeting of the
board of directors need be specified in the notice or waiver of notice of any
special meeting.

        3.10 Quorum; Majority Vote. At all meetings of the board of directors, a
majority of the number of directors fixed in the manner provided in these bylaws
shall constitute a quorum for the transaction of business. If a quorum is not
present at a meeting, a majority of the directors present may adjourn the
meeting from time to time, without notice other than an announcement at the
meeting, until a quorum is present. The


                                        6






act of a majority of the directors present at a meeting at which a quorum is in
attendance shall be the act of the board of directors, unless the act of a
greater number is required by law, the articles of incorporation, or these
bylaws.

        3.11 Procedure; Minutes. At meetings of the board of directors, business
shall be transacted in such order as the board of directors may determine from
time to time. The board of directors shall appoint at each meeting a person to
preside at the meeting and a person to act as secretary of the meeting. The
secretary of the meeting shall prepare minutes of the meeting which shall be
delivered to the secretary of the Corporation for placement in the minute books
of the Corporation.

        3.12 Presumption of Assent. A director of the Corporation who is present
at any meeting of the board of directors at which action on any matter is taken
shall be presumed to have assented to the action unless his dissent shall be
entered in the minutes of the meeting or unless he shall file his written
dissent to such action with the person acting as secretary of the meeting before
the adjournment thereof or shall forward any dissent by certified or registered
mail to the secretary of the Corporation immediately after the adjournment of
the meeting. Such right to dissent shall not apply to a director who voted in
favor of such action.

        3.13 Compensation. Directors, in their capacity as directors, may
receive, by resolution of the board of directors, a fixed sum and expenses of
attendance, if any, for attending meetings of the board of directors or a stated
salary. No director shall be precluded from serving the Corporation in any other
capacity or receiving compensation therefor.

        3.14 Action Without Meeting. Any action which may be taken, or which is
required by law, the articles of incorporation, or these bylaws to be taken, at
a meeting of the board of directors or any committee may be taken without a
meeting if a consent in writing, setting forth the action so taken, shall have
been signed by all of the members of the board of directors or committee, as the
case may be, and such consent shall have the same force and effect, as of the
date stated therein, as a unanimous vote of such members of the board of
directors or committee, as the case may be, and may be stated as such in any
document or instrument filed with the Secretary of State of Texas or in any
certificate or other document delivered to any person. The consent may be in one
or more counterparts so long as each director or committee member signs one of
the counterparts. The signed consent shall be placed in the minute books of the
Corporation.


                            ARTICLE FOUR: COMMITTEES





                                        7







        4.01 Designation. The board of directors may, by resolution adopted by a
majority of the entire board of directors, designate one or more committees.

        4.02 Number; qualification; Term. The board of directors, by resolution
adopted by a majority of the entire board of directors, shall designate one or
more of its members as members of any committee and may designate one or more of
its members as alternate members of any committee, who may, subject to any
limitations imposed by the board of directors, replace absent or disqualified
members at any meeting of that committee. The number of committee members may be
increased or decreased from time to time by resolution adopted by a majority of
the entire board of directors. Each committee member shall serve as such until
the earliest of (i) the expiration of his term as director, (ii) his resignation
as a committee member or as a director, or (iii) his removal, as a committee
member or as a director.

        4.03 Authority. Each committee, to the extent expressly provided in the
resolution establishing such committee, shall have and may exercise all of the
authority of the board of directors, including, without limitation, the
authority to authorize a distribution and to authorize the issuance of shares of
the Corporation. Notwithstanding the foregoing, however, no committee shall have
the authority of the board of directors in reference to:

                (a)     amending the articles of incorporation, except that a
                        committee may, to the extent provided in the resolution
                        designating that committee, exercise the authority of
                        the board of directors vested in it in accordance with
                        Article 2.13 of the Texas Business Corporation Act;

                (b)     proposing a reduction of the stated capital of the
                        Corporation in the manner permitted by Article 4.12 of
                        the Texas Business Corporation Act;

                (c)     approving a plan of merger or share exchange of the
                        Corporation;

                (d)     recommending to the shareholders the sale, lease, or
                        exchange of all or substantially all of the property and
                        assets of the Corporation otherwise than in the usual
                        and regular course of its business;

                (e)     recommending to the shareholders a voluntary dissolution
                        of the Corporation or a revocation thereof;

                (f)     amending, altering, or repealing these bylaws or
                        adopting new bylaws of the Corporation;

                (g)     filling vacancies in the board of directors;


                                        8






                (h)     filling vacancies in, or designating alternate members
                        of, any committee;

                (i)     filling any directorship to be filled by reason of an
                        increase in the number of directors;

                (j)     electing or removing officers of the Corporation or
                        members or alternate members of any committee;

                (k)     fixing the compensation of any member or alternate
                        member of any committee; or

                (l)     altering or repealing any resolution of the board of
                        directors that by its terms provides that it shall not
                        be amendable or repealable.

        4.04    Committee Changes. The board of directors shall have the power
at any time to fill vacancies in, to change the membership of, and to discharge
any committee.

        4.05    Regular Meetings. Regular meetings of any committee may be held
without notice at such time and place as may be designated from time to time by
the committee and communicated to all members thereof.

        4.06    Special Meetings. Special meetings of any committee may be held
whenever called by any committee member. The committee member calling any
special meeting shall cause notice of such special meeting, including therein
the time and place of such special meeting, to be given to each committee member
at least two days before such special meeting. Neither the business to be
transacted at, nor the purpose of, any special meeting of any committee need be
specified in the notice or waiver of notice of any special meeting.

        4.07    Quorum; Majority Vote. At meetings of any committee, a majority
of the number of members designated by the board of directors shall constitute a
quorum for the transaction of business. If a quorum is not present at a meeting
of any committee, a majority of the members present may adjourn the meeting from
time to time, without notice other than an announcement at the meeting, until a
quorum is present. The act of a majority of the members present at any meeting
at which a quorum is in attendance shall be the act of a committee, unless the
act of a greater number is required by law, the articles of incorporation, or
these bylaws.

        4.08    Minutes. Each committee shall cause minutes of its proceedings
to be prepared and shall report the same to the board of directors upon the
request of the board


                                        9



of directors. The minutes of the proceedings of each committee shall be
delivered to the secretary of the Corporation for placement in the minute books
of the Corporation.

        4.09    Compensation. Committee members may, by resolution of the board
of directors, be allowed a fixed sum and expenses of attendance, if any, for
attending any committee meetings or a stated salary.

        4.10    Responsibility. The designation of any committee and the
delegation of authority to it shall not operate to relieve the board of
directors or any director of any responsibility imposed upon it or such director
by law.


              ARTICLE FIVE: GENERAL PROVISIONS RELATING TO MEETINGS


        5.01    Notice. Whenever by law, the articles of incorporation, or these
bylaws, notice is required to be given to any committee member, director, or
shareholder and no provision is made as to how such notice shall be given, it
shall be construed to mean that any such notice may be given (a) in person, (b)
in writing, by mail, postage prepaid, addressed to such committee member,
director, or shareholder at his address as it appears on the books of the
Corporation or, in the case of a shareholder, the share transfer records of the
Corporation, or (c) by any other method permitted by law. Any notice required or
permitted to be given by mail shall be deemed to be delivered and given at the
time when the same is deposited in the United States mail, postage prepaid, and
addressed as aforesaid.

        5.02    Waiver of Notice. Whenever by law, the articles of
incorporation, or these bylaws, any notice is required to be given to any
committee member, shareholder, or director of the Corporation, a waiver thereof
in writing signed by the person or persons entitled to such notice, whether
before or after the time notice should have been given, shall be equivalent to
the giving of such notice. Attendance of a committee member, shareholder, or
director at a meeting shall constitute a waiver of notice of such meeting,
except where such person attends for the express purpose of objecting to the
transaction of any business on the ground that the meeting is not lawfully
called or convened.

        5.03    Telephone and Similar Meetings. Shareholders, directors, or
committee members may participate in and hold a meeting by means of a conference
telephone or similar communications equipment by means of which persons
participating in the meeting can hear each other. Participation in such a
meeting shall constitute presence in person at such meeting, except where a
person participates in the meeting for the express purpose of objecting to the
transaction of any business on the ground that the meeting is not lawfully
called or convened.


                                       10



















                                       11



                     ARTICLE SIX: OFFICERS AND OTHER AGENTS


        6.01    Number; Titles; Election; Term; Qualification. The officers of
the Corporation shall be a president, one or more vice presidents (and, in the
case of each vice president, with such descriptive title, if any, as the board
of directors shall determine), a secretary, and a treasurer. The Corporation may
also have a chairman of the board, one or more assistant treasurers, one or more
assistant secretaries, and such other officers and such agents as the board of
directors may from time to time elect or appoint. The board of directors shall
elect a president, vice president, treasurer, and secretary at its first meeting
at which a quorum shall be present after the annual meeting of shareholders or
whenever a vacancy exists. The board of directors then, or from time to time,
may also elect or appoint one or more other officers or agents as it shall deem
advisable. Each officer and agent shall hold office for the term for which he is
elected or appointed and until his successor has been elected or appointed and
qualified. Any person may hold any number of offices. No officer or agent need
be a shareholder, a director, a resident of the State of Texas, or a citizen of
the United States.

        6.02    Removal. Any officer or agent elected or appointed by the board
of directors may be removed by the board of directors whenever in its judgment
the best interest of the Corporation will be served thereby, but such removal
shall be without prejudice to the contract rights, if any, of the person so
removed. Election or appointment of an officer or agent shall not of itself
create contract rights.

        6.03    Vacancies. Any vacancy occurring in any office of the
Corporation may be filled by the board of directors.

        6.04    Authority. Officers shall have such authority and perform such
duties in the management of the Corporation as are provided in these bylaws or
as may be determined by resolution of the board of directors not inconsistent
with these bylaws.

        6.05    Compensation. The compensation, if any, of officers and agents
shall be fixed from time to time by the board of directors; provided, that the
board of directors may by resolution delegate to any one or more officers of the
Corporation the authority to fix such compensation.

        6.06    Chairman of the Board. The chairman of the board shall have such
powers and duties as may be prescribed by the board of directors.

        6.07    President. Unless and to the extent that such powers and duties
are expressly delegated to a chairman of the board by the board of directors,
the president shall be the chief executive officer of the Corporation and,
subject to the supervision of the board of directors, shall have general
management and control of the business and


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property of the Corporation in the ordinary course of its business with all such
powers with respect to such general management and control as may be reasonably
incident to such responsibilities, including, but not limited to, the power to
employ, discharge, or suspend employees and agents of the Corporation, to fix
the compensation of employees and agents, and to suspend, with or without cause,
any officer of the Corporation pending final action by the board of directors
with respect to continued suspension, removal, or reinstatement of such officer.
The president may, without limitation, agree upon and execute all division and
transfer orders, bonds, contracts, and other obligations in the name of the
Corporation.

        6.08 Vice Presidents. Each vice president shall have such powers and
duties as may be prescribed by the board of directors or as may be delegated
from time to time by the president and (in the order as designated by the board
of directors, or in the absence of such designation, as determined by the length
of time each has held the office of vice president continuously) shall exercise
the powers of the president during that officer's absence or inability to act.
As between the Corporation and third parties, any action taken by a vice
president in the performance of the duties of the president shall be conclusive
evidence of the absence or inability to act of the president at the time such
action was taken.

        6.09 Treasurer. The treasurer shall have custody of the Corporation's
funds and securities, shall keep full and accurate accounts of receipts and
disbursements, and shall deposit all moneys and valuable effects in the name and
to the credit of the Corporation in such depository or depositories as may be
designated by the board of directors. The treasurer shall audit all payrolls and
vouchers of the Corporation, receive, audit, and consolidate all operating and
financial statements of the Corporation and its various departments, shall
supervise the accounting and auditing practices of the Corporation, and shall
have charge of matters relating to taxation. Additionally, the treasurer shall
have the power to endorse for deposit, collection, or otherwise all checks,
drafts, notes, bills of exchange, and other commercial paper payable to the
Corporation and to give proper receipts and discharges for all payments to the
Corporation. The treasurer shall perform such other duties as may be prescribed
by the board of directors or as may be delegated from time to time by the
president.

        6.10 Assistant Treasurers. Each assistant treasurer shall have such
powers and duties as may be prescribed by the board of directors or as may be
delegated from time to time by the president. The assistant treasurers (in the
order as designated by the board of directors or, in the absence of such
designation, as determined by the length of time each has held the office of
assistant treasurer continuously) shall exercise the powers of the treasurer
during that officer's absence or inability to act. As between the Corporation
and third parties, any action taken by an assistant treasurer in the performance
of the duties of the treasurer shall be conclusive evidence of the absence or
inability to act of the treasurer at the time such action was taken.


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        6.11 Secretary. The secretary shall maintain minutes of all meetings of
the board of directors, of any committee, and of the shareholders or consents in
lieu of such minutes in the Corporation's minute books, and shall cause notice
of such meetings to be given when requested by any person authorized to call
such meetings. The secretary may sign with the president, in the name of the
Corporation, all contracts of the Corporation and affix the seal of the
Corporation thereto. The secretary shall have charge of the certificate books,
share transfer records, stock ledgers, and such other stock books and papers as
the board of directors may direct, all of which shall at all reasonable times be
open to inspection by any director at the office of the Corporation during
business hours. The secretary shall perform such other duties as may be
prescribed by the board of directors or as may be delegated from time to time
by the president.

        6.12 Assistant Secretaries. Each assistant secretary shall have such
powers and duties as may be prescribed by the board of directors or as may be
delegated from time to time by the president. The assistant secretaries (in the
order designated by the board of directors or, in the absence of such
designation, as determined by the length of time each has held the office of
assistant secretary continuously) shall exercise the powers of the secretary
during that officer's absence or inability to act. As between the Corporation
and third parties, any action taken by an assistant secretary in the performance
of the duties of the secretary shall be conclusive evidence of the absence or
inability to act of the secretary at the time such action was taken.


                  ARTICLE SEVEN: CERTIFICATES AND SHAREHOLDERS


        7.01 Certificated and Uncertificated Shares. The shares of the
Corporation may be either certificated shares or uncertificated shares. As used
herein, the term "certificated shares" means shares represented by instruments
in bearer or registered form, and the term "uncertificated shares" means shares
not represented by instruments and the transfers of which are registered upon
books maintained for that purpose by or on behalf of the Corporation.

        7.02 Certificates for Certificated Shares. The certificates representing
certificated shares of stock of the Corporation shall be in such form as shall
be approved by the board of directors in conformity with law. The certificates
shall be consecutively numbered, shall be entered as they are issued in the
books of the Corporation or in the records of the Corporation's designated
transfer agent, if any, and shall state upon the face thereof: (a) that the
Corporation is organized under the laws of the State of Texas; (b) the name of
the person to whom issued; (c) the number and class of shares and the
designation of the series, if any, which such certificate represents; (d) the
par value of each share represented by such certificate, or a statement that the
shares are without par


                                       14








value; and (e) such other matters as may be required by law. The certificates
shall be signed by the president or any vice president and also by the
secretary, an assistant secretary, or any other officer; however, the signatures
of any of such officers may be facsimiles. The certificates may be sealed with
the seal of the Corporation or a facsimile thereof.

        7.03 Issuance. Shares with or without par value may be issued for such
consideration and to such persons as the board of directors may from time to
time determine, except in the case of shares with par value the consideration
must be at least equal to the par value of such shares. Shares may not be issued
until the full amount of the consideration has been paid. After the issuance of
uncertificated shares, the Corporation or the transfer agent of the Corporation
shall send to the registered owner of such uncertificated shares a written
notice containing the information required to be stated on certificates
representing shares of stock as set forth in Section 7.02 above and such
additional information as may be required by Section 8.408 of the Texas Uniform
Commercial Code as currently in effect and as the same may be amended from time
to time hereafter.

        7.04 Consideration for Shares. The consideration for the issuance of
shares shall consist of money paid, labor done (including services actually
performed for the Corporation), or property (tangible or intangible) actually
received. Neither promissory notes nor the promise of future services shall
constitute payment or part payment for the issuance of shares. In the absence of
fraud in the transaction, the judgment of the board of directors as to the value
of consideration received shall be conclusive. When consideration, fixed as
provided by law, has been paid, the shares shall be deemed to have been issued
and shall be considered fully paid and nonassessable. The consideration received
for shares shall be allocated by the board of directors, in accordance with law,
between stated capital and surplus accounts.

        7.05 Lost, Stolen, or Destroyed Certificates. The Corporation shall
issue a new certificate or certificates in place of any certificate representing
shares previously issued if the registered owner of the certificate:

                (a)     Claim. Makes proof by affidavit, in form and substance
                        satisfactory to the board of directors or any proper
                        officer, that a previously issued certificate
                        representing shares has been lost, destroyed, or stolen;

                (b)     Timely Request. Requests the issuance of a new
                        certificate before the Corporation has notice that the
                        certificate has been acquired by a purchaser for value
                        in good faith and without notice of an adverse claim;



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                (c)     Bond. If required by the board of directors or any
                        proper officer, in its or such officer's discretion,
                        delivers to the Corporation a bond or indemnity
                        agreement in such form, with such surety or sureties,
                        and with such fixed or open penalty, as the board of
                        directors or such officer may direct, in its or such
                        officer's discretion, to indemnify the Corporation (and
                        its transfer agent and registrar, if any) against any
                        claim that may be made on account of the alleged loss,
                        destruction, or theft of the certificate; and

                (d)     Other Requirements. Satisfies any other reasonable
                        requirements imposed by the board of directors.

        7.06 Transfer of Shares. Shares of stock of the Corporation shall be
transferable only on the books of the Corporation by the shareholders thereof in
person or by their duly authorized attorneys or legal representatives. With
respect to certificated shares, upon surrender to the Corporation or the
transfer agent of the Corporation for transfer of a certificate representing
shares duly endorsed and accompanied by any reasonable assurances that such
endorsements are genuine and effective as the Corporation may require and after
compliance with any applicable law relating to the collection of taxes, the
Corporation or its transfer agent shall, if it has no notice of an adverse claim
or if it has discharged any duty with respect to any adverse claim, issue one or
more new certificates to the person entitled thereto, cancel the old
certificate, and record the transaction upon its books. With respect to
uncertificated shares, upon delivery to the Corporation or the transfer agent of
the Corporation of an instruction originated by an appropriate person (as
prescribed by Section 8.308 of the Texas Uniform Commercial Code as currently in
effect and as the same may be amended from time to time hereafter) and
accompanied by any reasonable assurances that such instruction is genuine and
effective as the Corporation may require and after compliance with any
applicable law relating to the collection of taxes, the Corporation or its
transfer agent shall, if it has no notice of an adverse claim or has discharged
any duty with respect to any adverse claim, record the transaction upon its
books, and shall send to the new registered owner of such uncertificated shares,
and, if the shares have been transferred subject to a registered pledge, to the
registered pledge, a written notice containing the information required to be
stated on certificates representing shares of stock set forth in Section 7.02
above and such additional information as may be required by Section 8.408 of the
Texas Uniform Commercial Code as currently in effect and as the same may be
amended from time to time hereafter.

        7.07 Registered Shareholders. The Corporation shall be entitled to treat
the shareholder of record as the shareholder in fact of any shares and,
accordingly, shall not be bound to recognize any equitable or other claim to or
interest in such shares on the part of any other person, whether or not it shall
have actual or other notice thereof, except as otherwise provided by law.


                                       16








        7.08 Legends. The board of directors shall cause an appropriate legend
to be placed on certificates representing shares of stock as may be deemed
necessary or desirable by the board of directors in order for the Corporation to
comply with applicable federal or state securities or other laws.

        7.09 Regulations. The board of directors shall have the power and
authority to make all such rules and regulations as it may deem expedient
concerning the issue, transfer, registration, or replacement of certificates
representing shares of stock of the Corporation.


                     ARTICLE EIGHT: MISCELLANEOUS PROVISIONS


        8.01 Dividends. Subject to provisions of applicable statutes and the
articles of incorporation, dividends may be declared by and at the discretion of
the board of directors at any meeting and may be paid in cash, in property, or
in shares of stock of the Corporation.

        8.02 Books and Records. The Corporation shall keep books and records of
account and shall keep minutes of the proceedings of its shareholders, the board
of directors, and each committee of the board of directors. The Corporation
shall keep at its registered office or principal place of business, or at the
office of its transfer agent or registrar, a record of the original issuance of
shares issued by the Corporation and a record of each transfer of those shares
that have been presented to the Corporation for registration of transfer, giving
the names and addresses of all past and current shareholders and the number and
class of the shares held by each of such shareholders.

        8.03 Fiscal Year. The fiscal year of the Corporation shall be fixed by
the board of directors; provided, that if such fiscal year is not fixed by the
board of directors and the board of directors does not defer its determination
of the fiscal year, the fiscal year shall be the calendar year.

        8.04 Seal. The seal, if any, of the Corporation shall be in such form
as may be approved from time to time by the board of directors. If the board of
directors approves a seal, the affixation of such seal shall not be required to
create a valid and binding obligation against the Corporation.

        8.05 Attestation by the Secretary. With respect to any deed, deed of
trust, mortgage, or other instrument executed by the Corporation through its
duly authorized officer or officers, the attestation to such execution by the
secretary of the Corporation shall not be necessary to constitute such deed,
deed of trust, mortgage, or other


                                       17










instrument a valid and binding obligation against the Corporation unless the
resolutions, if any, of the board of directors authorizing such execution
expressly state that such attestation is necessary.

        8.06 Resignation. Any director, committee member, officer, or agent may
resign by so stating at any meeting of the board of directors or by giving
written notice to the board of directors, the president, or the secretary. Such
resignation shall take effect at the time specified in the statement made at the
board of directors' meeting or in the written notice, but in no event may the
effective time of such resignation be prior to the time such statement is made
or such notice is given. If no effective time is specified in the resignation,
the resignation shall be effective immediately. Unless a resignation specifies
otherwise, it shall be effective without being accepted.

        8.07 Securities of Other Corporations. The president or any vice
president of the Corporation shall have the power and authority to transfer,
endorse for transfer, vote, consent, or take any other action with respect to
any securities of another issuer which may be held or owned by the Corporation
and to make, execute, and deliver any waiver, proxy, or consent with respect to
any such securities.

        8.08 Amendment of Bylaws. The power to amend or repeal these bylaws or
to adopt new bylaws is vested in the board of directors, but is subject to the
right of the shareholders to amend or repeal these bylaws or to adopt new
bylaws.

        8.09 Invalid Provisions. If any part of these bylaws is held invalid or
inoperative for any reason, the remaining parts, so far as is possible and
reasonable, shall remain valid and operative.

        8.10 Headings; Table of Contents. The headings and table of contents
used in these bylaws are for convenience only and do not constitute matter to be
construed in the interpretation of these bylaws.

        The undersigned, the secretary of the Corporation, hereby certifies that
the foregoing bylaws were adopted by the board of directors of the Corporation
as of September 29, 1995.



                                              /s/ Don G. Hicks
                                            ----------------------------
                                            Don G. Hicks, Secretary






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