10. (1) A casual vacancy in the office of a Director shall be filled by appointment or election, as the case may be, and a Director elected to fill a vacancy shall hold office for the unexpired period of the terms of his predecessor: Provided that it shall not be necessary to fill in a casual vacancy in the office of a Director for a period of less than three months. (2) If a Director is unable to attend the meeting of the Corporation for a period of three months or more, a person shall be appointed to act for such Director during his absence and the person so acting shall be deemed for all purposes to be a Director.