§ 11. "That, save in so far as may be otherwise provided by any Act of the present Session relating to Finance, animals and other living creatures kept for the purposes of farming or for the purposes of any trade whatsoever shall be treated for income tax purposes as trading stock or, in so far as an option conferred by the said Act to have them treated on an alternative basis has been duly exercised as respects them, on that alternative basis; and that where such an option is availed of or is or has been or may become available, such other consequences shall ensue for income tax purposes to all persons then or thereafter concerned as may be provided by the said Act."