All casual vacancies arising out of disqualification, death, resignation or removal among members of the Board or of any Committee appointed by the Board under Section 19 other than Ex officio members shall be filled as soon as may be, by election nomination co-option or appointment, as the case may be, according to the nature of vacancy and the person succeeding to such vacancy shall hold office as long as the member in whose place he is elected, nominated, co-opted or appointed would have held it if the vacancy had not occurred.