The circumstances that give rise to this second appeal may briefly be stated thus : — Sarv Shri Surat Ram and Rangilal sons of Ganeshlal brought a suit against Ghasilal, Jagting and Kesha minor with his mother as guardian for redemption of mortgage over the land in dispute with allegations that Smt. Harkubai the original owner (Bapidar) mortgaged the disputed land with possession in favour of Ghasilal about 15 years ago, that about 4-5 years ago defendant No. 1 subsequently mortgaged the same property in favour of the deceased father of defendants No. 2 and 3, in lieu of Rs. 632 and since then defendants No. 2 and 3 are in possession of the same. It was further alleged by the plaintiffs that Smt. Harkubai made a gift of the land in their favour and hence it was alleged, they were entitled to redeem the property. Defendant No. 1 admitted the suit. Defendants No. 2 and 3 contested the suit and pleaded that on Chait Sudi 10, 1999 the plaintiffs father had sold the land in their favour for Rs. 1032/- and hence no question of any redemption could possibly arise. It may be mentioned here that the defendants produced a copy of this sale deed along with their written statement dated 13.1.49 and subsequently wanted to confront the plaintiff Surat Ram with the original during the course of the cross examination but the trial court refused permission in that behalf on the ground that the sale deed was unregistered. Surat Ram plaintiff, however, produced a document marked Ex. D/1 and admitted that it related to the sale of the land in dispute and it was executed in favour of his father the defendant No.3. The following issues were framed by the trial court :— (1) Was the land in dispute fold by the father of the plaintiffs in favour of defendants No. 2 and 3 and whether the plaintiffs have no right to redeem the property. (2) In case the above issue is decided against the defendants then did they spend Rs. 1,000/-on the improvement of the land and would he entitled to get it before redemption. (3) Was document Ex. P. 1 obtained through fraud? (4) Has there been part performance after execution of the document and with what adverse effect against the plaintiffs. (2) In case the above issue is decided against the defendants then did they spend Rs. 1,000/-on the improvement of the land and would he entitled to get it before redemption. (3) Was document Ex. P. 1 obtained through fraud? (4) Has there been part performance after execution of the document and with what adverse effect against the plaintiffs. After recording the evidence of the parties the trial court came to the conclusion that the father of the plaintiffs sold the land as alleged by the defendants inasmuch as Surat Ram plaintiff had admitted in his statement but as the document was not "completed it cannot be held that the possession of the defendants ceased to be that of mortgage". As for sec. 53-A of the T. P. Act the trial court held that this Act was enforced in 1949 and as the suit was instituted in 1948 and hence the defendants cannot derive any benefit from it. Issue No. 2 was decided against the defendants. As regards issue No. 3, it was held by the trial court that no fraud was proved by the plaintiffs. As for the settlement parchas produced by the defendants it was held that they were on the basis of possession and hence were not of much significance and were open for correction. The suit of the plaintiffs was therefore decreed. In first appeal the learned Commissioner after narrating the case of the parties at great length held that the sale of land made by the father of the plaintiffs was not open to any doubt. It was also held that a sum of Rs. 400/- remained unpaid in this transaction and the father of the plaintiffs obtained a hand note in respect of this amount from the defendants. But the appeal was rejected with this observation that as the sale deed was of a valuation of Rs. 100 upwards and as it was unregistered it could not give rise to a valid transaction of sale and hence the mortgage must be deemed to be subsisting. Hence this second appeal by the defendants. We have heard the learned counsel for the parties and have examined the record as well. 100 upwards and as it was unregistered it could not give rise to a valid transaction of sale and hence the mortgage must be deemed to be subsisting. Hence this second appeal by the defendants. We have heard the learned counsel for the parties and have examined the record as well. The only question involved in this second appeal before us is as to whether after accepting the concurrent findings of the lower courts on questions of fact the decision of the lower court would be tenable or not. As observed above both the lower courts have held that there was a transaction of sale of land, or to be more accurate of the equity of redemption, between the father of the plaintiffs and the father of the defendant No. 3. An unregistered document also exists. Besides the plaintiffs themselves had in their possession a hand note of Rs.400/- executed in favour of their father in respect of the unpaid amount of this transaction. It was produced by them. Surat Ram in his statement admitted this transaction. The lower courts based their decision only on the ground that as the sale deed was unregistered the mortgage should be deemed to be subsisting unaffected by this transaction of sale. We have to determine the validity of the above proposition. The first question in this connection relates to the effect of want of registration of the sale deed. It is established law that an unregistered sale deed cannot be admitted to prove a sale as such of the disputed land in favour of the defendants. But it can in our opinion be legitimately used to show the nature and quality of their possession over the land in dispute and to which it pertains. Such a matter is really a collateral one within the meaning of sec. 49 of the Registration Act and hence an unregistered document would be admissible as evidence of the nature and character of possession held under the deed. Barkat All versus Girdhari Singh 1955 R.L.W. page 472 may be cited in support of this proposition. The learned counsel for the plaintiffs has cited Kashiram Vs. Bhursingh decided by the Rajasthan High Court on 3 1st October 1949. In that case their Lordships were pleased to observe that the Transfer of Property Act was applied to the former Udaipur State, in the year 1948 and as such sec. The learned counsel for the plaintiffs has cited Kashiram Vs. Bhursingh decided by the Rajasthan High Court on 3 1st October 1949. In that case their Lordships were pleased to observe that the Transfer of Property Act was applied to the former Udaipur State, in the year 1948 and as such sec. 53A of that Act could have no application to suits which were filed before it. In other words the question as to whether an unregistered sale deed could or could not be examined for collateral purposes was not involved for determination in that case and hence this ruling is clearly distinguishable. As a general proposition it is true that the doctrine "once a mortgage always a mortgage is a well established one. But the plaintiffs were bound further to prove that the mortgage sought to be redeemed by them was a subsisting one. In the present case we are clearly of the opinion that they have so failed. The unregistered sale deed is clearly admissible to prove the nature and quality of the possession of the defendants. In fact, besides this unregistered document there is over-whelming evidence to prove that the land (equity of redemption) was sold in favour of the defendants by the father of the plaintiffs. There is the statement of Surat Ram plaintiff himself coupled with a document produced by him which makes a clear mention of the transaction of sale. Under these circumstances it is not open to the plaintiffs to plead that as the deed was not registered the transaction itself should be overlooked completely. Where the question would have been to enforce the transaction itself the plea of the plaintiffs may have prevailed. But in the present case the only question is to determine the nature and quality of the possession of the defendants after the alleged transaction of sale and to this one and only one answer is possible namely that the nature of possession changed from that of a mortgagee to that of a vendee. To conclude therefore we hold that the judgment and decrees of the lower courts are clearly untenable. We therefore, allow this appeal, set aside the judgment and decrees of the lower courts and direct that the suit of the plaintiffs shall stand rejected throughout.