(a) Shares which are held jointly or as tenants in common by two or more persons, as fiduciaries or otherwise, shall be deemed to be represented for the purpose of determining a quorum if one or more such persons are present in person or by proxy. Except as provided in subsection (b) of this section, the vote of all such shares shall be the vote cast by such person or a majority of such persons but if such persons are equally divided upon the manner of voting, the vote of the shares held by them shall be divided equally among such persons, without prejudice to the rights of such joint owners or the beneficial owners thereof among themselves.

(b) Upon the filing with the secretary of the institution of a copy, certified by an attorney-at-law to be correct, of the relevant portions of the agreement under which such shares are held or of the instrument or decree of court by which the fiduciaries were appointed, or of a decree of court directing the voting of such shares, the persons specified as having such voting power in the latest such document shall be entitled to vote such shares in accordance therewith.