1. It is not now disputed that the discharge of the mortgage-debt represented by Ex. A by the payment and receipt of a smaller amount than was due can be proved as a fact if it is sepaparable from any oral agreement to vary the terms of the mortgage contract and can be proved without evidence of such an agreement: Balusundara Naicker v. Ranganatha Aiyar A.I.R. 1929 Mad. 794. In this case the plaintiff pleaded such on oral agreement of 25th June 1919. But the learned Subordinate Judge found that the discharge of the mortgage by payment of Rs. 1,500 on 5th July 1919 was true without referring to the alleged agreement to vary the terms of the mortgage and without using any evidence regarding that agreement. It is objected that he used the endorsement of discharge on Ex. A, which it is contended, was inadmissible in evidence because it was unregistered. But that endorsement in our opinion comes within Section 17(2)(11), Registration Act, and need not have been registered.
2. Without discussing on this occasion the question whether all endorsements of payment on mortgage-deeds are exempt from registration or only those which do not purport to extinguish the mortgage we find in this case that the endorsement does not on its face purport to extinguish the mortgage. The return of the mortgage deed by the mortgagee is certainly not conclusive in such cases nor even of itself any indication that the mortgage is extinguished: Hari Narain Banerji v. Shamasundari Dasi 37Cal589, Piari Lal v. Makhan  34 All. 528 and Seshayya v. Subbamma : (1898)8MLJ269 . It is also suggested for the defendants that, if the oral agreement of 25th June 1919 to vary the mortgage contract cannot be proved, the agreement made on the same occasion to assign the decree against his father-in-law to the plaintiff, on which the plaintiff sues, also cannot be proved, as they were really parts of one agreement. But, because the plaintiff cannot prove any such agreement to vary the mortgage contract by taking less than what was due on it in full discharge, he is not necessarily shut out from proving the actual discharge of the mortgage by the payment and acceptance of a lesser amount and the payment of the balance, for which he now sues, in accordance with a separable agreement that defendant 1 should assign the decree to him.
3. In our opinion this appeal must be allowed and the Subordinate Judge's decree restored with costs throughout.