Filling of casual vacancies

All casual vacancies amongst the members other than ex-officio members of any authority or other body of the University shall be filled, as soon as may be by the person or body who or which nominated the member whose place has become vacant and the persons nominated to a casual vacancy shall be member of such authority or body for the residue of the term for which the person in whose place he is nominated would have been a member: Provided that no casual vacancy shall be filled, if such vacancy occurs within six months before the date of the expiry of the term of the members of any authority of the Executive Council.