" If immediately before the 1st day of April, 1950, there is in force in any Part B State other than Jammu and Kashmir or in Manipur, Tripura or Vindhya Pradesh or in the merged territory of CoochBehar any law relating to income tax or super tax or tax on profits of business that law shall cease to have effect except for the purposes of the levy, assess ment and collection of income tax and super tax in respect of any period not included in the previous year for the purposes of assessment under the Indian Income tax Act, 1922, for the year ending on the 31st day of March, 1951, or for any subsequent year, or, as the case may be, the levy, assessment and collection of the tax on profits of business for any chargeable accounting period ending on or before the 31st day of March, 1949: Provided that any reference in any such law to an officer, authority, tribunal or court shall be construed as a reference to the corresponding officer, authority, tribunal or court appointed or constituted under the said Act, and if any question arises as to who such corresponding officer, authority, tribunal or court is, the decision of the Central Government thereon shall be final.," Now, the legal effect of the constitutional changes referred to above, so far as it has a bearing on the present dispute, may be briefly summarised as follows: the Indian Income tax Act, 1922, remained in force in the retroceded area till June 30, 1948 ; from July 1, 1948, the Mysore Income tax Act, 1923, applied, subject to this saving that the Indian Income tax Act continued to apply in respect of the total income chargeable to income tax in the retroceded area prior to July 1, 1948, and the provisions of that Act as in force in the retroceded area prior to that date applied to all proceedings relating to the assessment of such income 795 upto the stage of assessment and determination of income tax payable thereon.