Summarize the following court judgment. Appeal No. 954 of 1963. On appeal. from the judgment and decree dated March 9	 1964	 of the Allahabad High Court in Income tax Miscellaneous Case No. 143 of 1954. 991 K. N. Rajagopala Sastri	 R. H. Dhebar and R. N. Sachthey	 for the appellant. A. V. Viswanatha Sastri	 Z. section Meeratwal	 B. P. Singh and Naunit Lal	 for the respondent. The Judgment of the Court was delivered by Subba Rao J. This appeal by special leave is directed against the order of a Division Bench of the High Court of Judicature at Allahabad holding that the Income tax Officer	 in the circumstances of the case	 went wrong in initiating proceedings under section 34(1) of the Indian Income tax Act	 1922	 hereinafter called the Act	 in respect of the assessment year 1942 43. The facts may briefly be stated. The assessee was a holder of an impartible estate in the district of Ajmer. On March 25	 1944	 the Income tax Officer assessed him to income tax for the year 1942 43. On April 5	 1945	 on the ground that two items of the assessee 's income	 namely	 s year (forest) income and interest income	 were not included in the original assessment	 a notice under section 34 of the Act was issued to him. In response to the said notice	 the assessee filed a return wherein he disclosed fully and completely the particulars of his interest income	 but raised the plea that his forest income was not taxable. The Income tax Officer	 by his order dated July 12	 1945	 made a revised assessment including both the incomes. The respondent eventually	took the matter on appeal to the Income tax Appellate Tribunal	 which	 by it 	 order dated April 25	 1949	 held that the Income tax Officer had no jurisdiction to initiate proceedings under section 34 of the Act in respect of the forest income on the ground that the Income tax Officer had knowledge that the assessee had such income when he made the original assessment. Though the Tribunal only dealt with the question of forest income	 by inadvertence or by mistake	 it set aside the entire order of reassessment dated July 12	 1945	 made by the Income tax Officer and restored the original order passed by him. The Income tax Department did not take any steps to rectify the mistake under section 35 of the Act or make any attempt to have the question of the illegality referred to the High Court. Having allowed the order to become final	 on January 3	 1950	 the Income tax Officer after obtaining the sanction of the Commissioner initiated proceedings under section 34 of the Act with respect to the interest income. On January 19	 1950	 the Income tax Officer issued to the assessee a fresh notice under the said section. On September 25	 1950	 a 992 revised assessment order was made in regard to the assessment year 1942 43 in which the respondent 's interest income was also included. On appeal	 the Appellate Assistant Commissioner confirmed the said order. On further appeal	 the 'Income tax Appellate Tribunal held that since the assessee had failed to disclose his interest income in the return filed by him under section 22(2) of the Act in connection with the original assessment the said income had escaped assessment and	 therefore	 the provisions of section 34 (1 ) (a) of the Act were attracted. On application filed by the assessee	 the Tribunal referred the following question to the High Court under section 66(1) of the Act: "Whether on the facts and in the circumstances of this case the provisions of section 34(1) were applicable in respect of the assessment year 1942 43 on 19th January	 1950	 when the notice under that provision was issued for the purpose of assessing the escaped interest income." The High Court came to the conclusion that the Tribunal in its order dated April 25	 1949	 committed a clear error in setting aside the assessment of tax on the interest income without going 	into the correctness of the imposition of tax thereon	 but that order had become final; it further held that the said order 	did not invalidate the entire proceedings taken under section 34 of the Act and	 therefore	 the Income tax Officer could not take proceedings afresh under section 34 of the Act. In the result the High Court answered the question in the negative. Hence the appeal. Mr. Rajagopala Sastri	 learned counsel for the Revenue	 con tended that the interest income had escaped assessment and	 therefore	 the Income tax Officer was competent to initiate proceedings under section 34(1) (a) of the Act for assessing the same. Mr. Viswanatha Sastri learned counsel for the respondent	 on the other hand	 argued that the assessment made by the Income tax Officer pursuant to the notice issued under section 34 of the Act was in its entirety set aside by the Tribunal on the ground that there was no "discovery" within the meaning of section 34 of the Act and that order had become final and	 therefore	 the Income tax Officer could not initiate fresh proceedings under that section on the 	principle of res judicata. To appreciate the contentions of the parties it is necessary to 	notice the scope of the order of the Tribunal dated April 25	 1949. Before the Appellate Tribunal it was contended on behalf of the assessee that the Income tax Officer who issued the said notice had 993 no definite information which led to the discovery that the said income had escaped assessment within the meaning of the said section. Adverting to the said argument the Tribunal observed: "We do not agree with the contention of the department that the Income tax Officer who made the original assessment did not apply his mind to this fact	 as there is no evidence to show that at the material time such income was considered taxable by the Department. Ordinarily one would expect that when an Income tax Officer makes the assessment he does according to law and on the facts as produced before him. If the fact is before him he refused to take it into account thinking that it was immaterial or even inadvertently takes no notice of it	 it cannot be said that the Income tax Officer came in possession of a definite information within the meaning of section 34. We are	 therefore	 of the opinion that proceedings. under section 34 could not be initiated against the assessee for the four assessment years under reference. The orders passed by the Income tax Officer in respect of these four years are therefore set aside and the original orders under section 23(3) are restored. " We have extracted the order in extenso as the argument really turns upon the scope of the said order. The Appellate Tribunal in considering the validity of the notice under section 34 of the Act only discussed the question of the escape of the year income; it did not advert to the interest income at all. It came to the conclusion	 having regard to the fact that the Income tax Officer at the time he made the original assessment had knowledge of the existence of the syar income	 that the Income tax Officer did not come into possession of definite information within the meaning of section 34 of the Act. Though the finding was arrived at on the basis of the syar income alone the Tribunal set aside the entire order of reassessment and restored the original order of assessment made by the Income tax Officer under section 23 (3) of the Act. The legal effect of the order was that the are assessment of the entire income	 including the syar income and interest income	 was set aside on the ground that the Income tax Officer did not come into possession of definite information leading to a "discovery" and	 therefore	 he could not initiate proceedings under section 34 of the Act. It is true that the Tribunal had committed a mistake in setting aside the reassessment order in respect of the interest income 994 also; but	 so long as that order stands	 it comprehends both the incomes. The Income tax Officer did not take any further proceedings by way of reference to the High Court on any question of law arising out of the order of the Tribunal; nor did he take any proceedings under section 35 of the Act to have the order corrected on the ground of mistake. With the result the order has become final. The question	 therefore	 is not whether the order of the Tribunal in so far as it related to the interest income was made by inadvertence or under a mistake	 but whether the Income tax Officer could initiate proceedings over again under section 34 of the Act in derogation of the finding given by the Tribunal that the Income tax Officer did not "discover" that the income had escaped assessment. The Income tax Act is a self contained one. It creates a hierarchy of tribunals with original	 appellate and revisional jurisdictions. Section 31 gives	 inter alia	 right of appeal against some orders of the Income tax Officer to the Appellate Assistant Commissioner; section 33 provides for a further appeal to the Income tax Appellate Tribunal; and sub section (6) of section 33 says that save as provided in section 66 orders passed by the Appellate Tribunal on appeal shall be final. Section 66 provides for reference to the High Court on a question of law; and section 66 A provides for appeals in certain cases to the Supreme Court. It is clear from the said provisions that the order of the Tribunal made within its jurisdiction	 subject to the provisions of section 66 of the Act	 is final. Therefore	 the decision of the Tribunal in respect of the subject matter under appeal before it is final and cannot be reopened by the assessee or the Department. The Judicial Committee in Commissioner of Income tar	 Bombay & Aden vs Khemchand Ramdas(1) succinctly stated the legal position thus : "But it is not true that after a final assessment under those sections (sections 23 and 29) has been made	 the Income tax Officer can go on making fresh computations and issuing fresh notices of demand to the end of all time. . But when once a final assessment is arrived at	 it cannot in Their Lordships ' opinion be reopened except in the circumstances detailed in (1) 	 424	 426. 995 Sections 34 and 35 of the Act and within the time limited by those sections. " Later on the same idea is restated thus "In Their Lordships opinion the provisions of the two sections are exhaustive	 and prescribe the only circumstances in which and the only time within which such fresh assessments can be made and fresh notices of demand can be issued. " The Judicial Committee again in Commissioner of Income tax	 West Punjab vs The Tribune Trust	 Lahore(1)	 after noticing the relevant sections of the Act	 reaffirmed the same position and held that assessments once made would be valid and effective until they were set aside in the manner prescribed by the Act and that	 if not so set aside	 they were final. If so	 it follows that the order of the Tribunal on the said question	 namely	 that the whole order of reassessment under section 34 of the Act was invalid as there was no "discovery" that the relevant income escaped assessment	 had become final. The only two sections that enable the Income tax Officer to reopen final assessments are sections 34 and 35. If the Appellate Tribunal committed a mistake	 under section 35 it can be rectified within four years from the date of the order. In the present case it was a clear case of mistake	 for the Tribunal set aside the order of reassessment in respect of the interest income	 though its validity to that extent was not disputed. But	 for one reason or other	 the Revenue did not resort to the obvious remedy and allowed the mistake to remain uncorrected. In the se circumstances	 can section 34 of the Act be resorted to ? Learned counsel for the Revenue says that section 34(1) (a)	 as amended in 1948	 confers such a power on the Income tax Officer. The material part of section 34	 before amendment	 read: "(1) If in consequence of definite information which has come	 into his possession the Income tax Officer discovers that income	 profits or gains chargeable to income tax have escaped assessment in any year Section 34 (1 ) (a)	 as amended in 1948	 reads : "If the Income tax Officer has reason to believe that by reason of the omission or failure on the part of in assessee to disclose fully and truly all material facts necessary for his assessment for that year. (1) 996 income	 profits or gains chargeable to income tax have escaped assessment for that year. he may in cases falling under clause (a) at any time. . . . serve on the assessee a notice. . . " It is said that the words "has reason to believe that by reason of the omission or failure on the part of an assessee to disclose fully and truly all material facts necessary for his assessment for that year	 income profits or gains chargeable to income tax have escaped assessment" are more comprehensive than the words "the Income tax Officer discovers that income etc.	 have escaped assessment in any year" and	 therefore	 though there was a finding by the Tribunal that the Income tax Officer did not "discover" that there was escape of assessment	. the Income tax Officer under the amended section 34 can initiate proceedings in spite of that finding. We cannot accept this argument. It could not have been the intention of the Legislature by amending the section to enable the Income tax Officer to reopen final decisions made against the Revenue in respect of questions that directly arose for decision in earlier proceedings. The Tribunal held in the earlier proceedings that the Income tax Officer knew all the facts at the time he made the original assessment in regard to the income he later on sought to tax. The said finding necessarily implies that the Income tax Officer had no reason to believe that because of the 'assessee 's failure to disclose the facts income has escaped assessment. The earlier finding is comprehensive enough to negative "any such reason" on the part of the Income	 tax Officer. That finding is binding on him. He could not on the same facts reopen the proceedings on the ground that he had new information. If he did so	 it would be a clear attempt to circumvent the said order	 which had become final. We are not concerned in this appeal with a case where the Income tax Officer got new information which he did not have at the time when the Tribunal made the order. The finding of the Tribunal is	 therefore	 binding on the Income Officer and he cannot	 in the circumstances of the case	 reopen the assessment and initiate proceedings over again. If that was not the legal position	 we would be placing an unrestricted power of review in the hands of an Income tax Officer to go behind the findings given by a hierarchy of tribunals and even those of the High Court and the Supreme Court with his changing moods. The decisions: cited by the learned counsel for the Revenue do not countenance such a contention. Chakraverti C.J.	 in 997 R. K. Das & Co. vs Commissioner of Income tax	 West Bengal(1)	 speaking for the Division Bench	 only decided that the Income tax Officer could not make a reassessment unless he issued the prescribed notice and issued it in a valid form. As the notice under section 34 of the Act issued therein was held to be bad inasmuch as the Income tax Officer did not take the sanction of the Commissioner	 the learned Chief Justice held that the returns filed pursuant to such notice was also bad. We are not here concerned with that aspect of the case. The judgment of this Court in Commissioner of Income tax	 Bihar & Orissa vs Maharaja Pratapsingh Bahadur of Gidhaur(2) held that	 as the earlier notice issued under section 34(1) of the Act without the sanction of the Commissioner was bad	 the entire proceedings for are assessment were illegal. There was an observation 'at the end of the judgment to the effect that "there was time enough for fresh notices to have been issued	 and we fail to see why the old notices were not recalled and fresh ones issued". The point now raised before us	 viz.	 how far and to what extent a final order made in earlier proceedings under section 34 of the Act would be binding on the Income tax Officer in subsequent proceedings under the said section was neither raised nor decided in that case. The said decisions	 therefore	 have no bearing an the question raised before us. For the foregoing reasons we hold that the answer given by the High Court to the question referred to it is correct. In the result	 the appeal fails and is dismissed with costs. Appeal dismissed.

The Income tax Officer issued a notice to the assessee under section 34 on the ground that two items of the assessee 's income	 namely forest income and interest income	 were not included in the original assessment for the year 1942 43. In response the assessee filed a return fully disclosing his interest income but raised the plea that his forest income was not taxable. The	 Income tax Officer however	 assessed both items to tax. On appeal	 the Appellate Tribunal in its order dated April 25	 1961	 although dealing only with the forest income and holding that the Income tax Officer had no jurisdiction to initiate proceedings under section 34 in respect of such income	 by inadvertence or by mistake	 set aside the entire order of reassessment both in respect of forest income	 as well as the interest income. The Department did not take any steps to rectify the mistake under section 35 or to have the question of illegality referred to the High Court. Having allowed the order of the Tribunal to become final	 the Income tax Officer initiated fresh proceedings under section 34 in respect of the interest income and made a revised assessment order which included this income. The Appellate Tribunal confirmed the assessment but the High Court	 on a reference to it under section 66(1)	 took the view that fresh proceedings under section 24 could not be taken for the reason	 inter alia	 that the Tribunal 's order dated April 25	 1949 had become final. HELD : The Tribunal had committed a mistake in setting aside the reassessment order in respect of interest income also	 but the income tax Officer did not resort to the obvious remedy of having the mistake rectified as provided for under section 35 and allowed the Tribunal 's order dated April 25	 1949 to become final. He could not in the circumstances	 reopen the assessment by initiating proceedings under section 34	 as otherwise there would be an unrestricted power of review in the hands of the Income tax Officer to go behind the findings of a hierarchy of Tribunals and Courts. [995 E F; 996 F H] C.I.T. Bombay and Aden vs Khemchand Ramdas	 (1938)6 I.T.R. 414 and C.I.T. West Punjab vs The Tribune Trust	 Lahore	 (1948)16 I.T.R. 214	 referred to. R. K. Das & Co. vs C.I.T.	 West Bengal	 (1956)30 I.T.R. 439 and C.I.T.	 Bihar & Orissa vs Maharaja Pratapsingh Bahadur of Gidhaur	 distinguished.