1. This is plaintiff's appeal against the decision of the Additional Subordinate Judge of Noakhali, dated 23rd June 1926, modifying a decision of the Munsif, Lakhipur, dated 25th August 1923. The suit in which this appeal arises was commenced by the plaintiff for recovery of Rs. 57-8-9 as arrears of rent together with cesses and interest for the years 1325 to 1328 B. S. in respect of a holding which the principal defendants hold under the plaintiff. The case of the plaintiff is that the defendant was holding the disputed land at a jama of Es 7-15 a year. He states that the rights between the parties were created by a kabuliyat which was executed on 28th Chaitra 1293, and that the plaintiff did not realize through mistake the jama at the rate Rs. 7-15 a year but realized it at the rate of Rs. 5 a year. The defence of the defendant in substance was that the defendant was holding this jama at a fixed rental of Rs. 5 a year. This defence did not prevail with the Court of first instance and the Munsif decreed in part for the rents of the period in suit at the rate of Rs. 7-15 a year and only varied the amount of interest. An appeal was taken to the Court of the Subordinate Judge of Noakhali and the learned Subordinate Judge held that the plaintiff was entitled to get rent at the rate of Rs. 5 a year. Before the Subordinate Judge it was contended by the defendants, now respondents, that although in the kabuliyat of 28th Chaitra 1293, there was a stipulation that after the Bengali year 1296 rent was to be realized at the rate of Rs. 7-15 a year, rent had been realized at the lower rate of Rs. 5 ever since that date and, consequently, there has been a waiver of the stipulation in the kabuliyat that the fixed rental was to be at the rate of Rs. 7-15 a year. This contention. of the defendant prevailed with the lower appellate Court and the lower appellate Court came to the finding that the explanation given by the plaintiff that the rent at the rate of Rs. 7-15 was not realized through mistake was not an explanation which he would accept and from the fact of non-realization of rent at the rate of Rs. 7-15 the Court of appeal came to the conclusion that there has been a waiver of this stipulation to pay a higher rate and that consequently the plaintiff could not claim rent at that rate. The Court of appeal also held that on the construction of the kabuliyat the defendant was holding a permanent mo-karrari lease under the plaintiff. In other words, the effect of the lower appellate Court's decision is that all the terms of the kabuliyat must be given effect to except the term which referred to the progressive increase of rent up to the limit of Rs. 7-15 which was to be the fixed rental for all times to come after the year 1296. In support of this decision, the lower appellate Court relied on three decisions of this Court in the cases of Beni Madhub Gorani v. Lalmoti Dassi  6 C.W.N. 242 and Kailash Chandra Saha v. Darbaria Sheikh  20 C.W.N. 347 and Manindra Chandra Nandi v. Sm. Durga Sundari Dassya  20 C.W.N. 680.
2. A second appeal has been taken to this Court against this decision of the Subordinate Judge and it has been argued by the learned vakil for the appellant that the decision of the lower appellate Court in so far as it decreed the plaintiff's suit at the reduced rate of Rs. 5 is wrong; firstly, because it was not permissible to the lower appellate Court to rely on the evidence of the acts and conduct of parties for the purpose of varying the terms of the original kabuliyat, and secondly, because in any event the mere fact of non-realization of rent for a large number of years does not necessarily give rise to the legal inference that there has been a waiver of the right to receive a fixed rent of Rs. 7-15 a year after 1296. We think that both these contentions are well-founded and must prevail. The case of Beni Madhub Gorani v. Lalmoti Dassi  6 C.W.N. 242 relied on by the lower appellate Court is obviously distinguishable. It will appear from the report of that case that there the question was as to whether the kabuliyat was ever acted upon. The kabuliyat stipulated a rate of rent to be Rs. 27 at the inception and after a certain number of years to be-Es. 30 and the rent which was paid was neither Rs. 27 nor Es. 30 and it was held that as the rent mentioned in the kabuliyat had not been paid for a large number of years, an inference might be drawn that the kabuliyat was not intended to be acted upon. In the present case, it is common ground that the kabuliyat was acted upon, so far as the realization of rent at the rate of Rs. 5 up to the year 1296 was concerned. It is not the case of the defendant that there was any contemporaneous agreement at the inception of the tenancy which was created by the kabuliyat that although it was stipulated that after 1296 the rent to be paid was Rs. 7-15, yet it was agreed that that stipulation was not to be given effect to. The case of the defendant is that by reason of non-realization of rent from 1296, there-has been a variation of that particular stipulation in the kabuliyat and as the kabuliyat was created by a registered instrument, such a variation or reduction of rent could only be made by another registered instrument. In this connexion, reference may be made to the provisions of Section 92, Clause (4), Evidence Act, and to two decisions, one of a Full Bench of this Court in the ease of Lalit Mohan Ghosh v. Gopali Chuck Coal Co., Ld.  39 Cal. 284 and to the case of Durga Prasad Singh v. Rajendra Narayan Bagchi  41 Cal. 493, which went before the Judicial Committee of the Privy Council. The case of Kailash Chandra Saha v. Darbaria Sheikh  20 C.W.N. 347 does undoubtedly lend some support to the contention raised by the learned vakil for the respondent and support the view taken by the Court of appeal below. To this case Nalini Ranjan Chatterjea, J. was a party and he considered the case of Kailash Chandra Saha v. Darbaria Sheikh  20 C.W.N. 347 in a later case, namely, in the case of Nagendra Lal Khan v. Bhola Nath Bhuya A.I.R. 1923 Cal. 417. At p. 338 (of 27 C. W. N.) Chatterjea, J. in delivering the judgment of the Court observed as follows:
It may be open to doubt, however, whether there can be a waiver o the essential terms of a registered lease except by a registered instrument having regard to the decision of the Full Bench in the case of Lalit Mohan Ghosh v. Gopali Chuck Coal Co. Ltd.  39 Cal. 284 where, however, the variation was sought to be effected by documents. But in the cases mentioned above, the Court held, upon the evidence of the subsequent acts and conducts of the parties, that certain terms of the contract were never intended to be acted upon. On the other hand, in the case of Lakhatulla v. Bishwambhar Roy  12 C.L.J. 646, Jenkins, C.J., and Doss, J. held that an agreement is none the less oral because it is to be inferred from the conduct of the parties.
3. The learned Judge then referred to the fact that this question was raised before the Judicial Committee in the ease of Maung Kyin v. Ma Shwe La  38 Cal. 892 but was not decided and he held again at p. 339 that although the decisions of some of the other High Courts took a view contrary to that taken by the Full Bench of this Court in Preonath v. Madhusudhan  25 Cal. 603, the question so far as this Court is concerned was not free from difficulty nor settled, although the weight of authority was in favour of the admissibility of evidence of the acts and conduct of parties and this Court has held in some cases upon the subsequent acts and conduct of parties that certain terms of a contract were never intended to be acted upon, i.e. from the very beginning. At the time of this decision in Narendra Lal Khan v. Bhola Nath Bhuya A.I.R. 1923 Cal. 417 the Judicial Committee, as the learned Judge points out, expressed no opinion on the question with regard to the admissibility of the evidence of the kind with which we have to deal. It appears, however, that the Judicial Committee did decide the question in 1917, as will appear from the report in the case of Maung Kyin v. Ma Shwe La A.I.R. 1917 P.C. 207. Apparently, the attention of the learned Judges who dealt with the case of Narendra Lal Khan v. Bhola Nath Bhuya A.I.R. 1923 Cal. 417 was not drawn to the case. Be that as it may, it seems to me from a reading of this decision that evidence of the kind with which we have to deal in the present case, namely, the acts and conduct of parties for the purpose of showing that the main or essential terms of an instrument has been varied is not admissible. Reference might be made in this connexion to the following observations of Lord Shaw in that case:
Founding upon this section, the respondents maintain that the whole of the evidence led must be rejected. On the contrary, the appellants maintain that notwithstanding the terms of the section, they are entitled to set up and prove the anta and conduit of the parties as inconsistent with the transfer of property and only consistent with the true nature of the transaction having been one of mortgage or transfer of mortgage. They found upon a considerable body of authority to that effect, etc., etc.
4. Their Lordships pointed out at p. 332 that the true rule seems to have been laid down in the case of Dattoo Totaram v. Ramchandra Totaram  30 Bom. 119 decided by Sir Lawrence Jenkins. We think that, having regard to the observations which I have quoted, it is extremely doubtful if the decision in Kailash Chandra Saha v. Darbaria Sheikh  20 C.W.N. 680 to which reference has already been made can be regarded as good law. Mr. Sen who has appeared for the respondent had to concede that in substance the effect of this relinquishment is really to vary the right of the plaintiff which was a right to receive the higher rate of rent. There has really been a substraction from that right and that variation can only be made by a registered instrument. We think the decision of the lower appellate Court is wrong.
5. With regard to ground 2 taken by the learned vakil for the appellant, as I have already stated, that also is a substantial ground and should be given effect to. It lay on the defendant to establish that there has been a permanent relinquishment of the right by the plaintiff to receive the higher rent. The fact of non-realization of rent for a large number of years might be consistent with a temporary abatement although the temporary abatement might extend over a large number of yews. The question of waiver or relinquishment is a question of legal inference from facts found. The question of waiver, acquiescence or estoppel is a question which can be examined by this Court in second appeal. In this connexion, reference may be made in the case of Beni Ram v. Kundan Lal  21 All. 496. We think that in order to establish an abandonment of right which is orated by a document which is explicit and unambiguous in its terms, something more than a mere non-enforcement of right over a number of years is necessary. It is conceded that there is nothing more in this case than the fact of non-realization of rent for a number of years. That alone would not justify us in holding that there has been a permanent abandonment of the right to receive a higher rent. The result is that the decree of the lower appellate Court must be set aside and that of the Munsif restored but in the circumstances of the present case, there will be no order as to costs.