Judgment :- 1. The petitioner applied for purchases of 981/4 cents of land, under S.72 B of Act I of 1964. This item, along with others, was in the possession of the 1st respondent's father under a usufructuary mortgage executed by the jenmies in 1078 M. E. In a family arrangement of the year 1117 M. E., the mortgage right (over the land in question) was allotted to the 1st respondent and he was in possession and enjoyment thereafter. In 1962, he gave the 981/4 cents on Otti to the present petitioner. 2. In the proceedings before the Tribunal, tenancy was claimed on the basis of S.4A(1) (a). The petitioner was admittedly a sub-mortgagee in possession from 1962 only; but it was urged that his mortgagor was in possession from 1078 M. E., and that this period could also be tacked on to make up the "continuous period of not less than fifty years" required under the statute. Explanation II was pressed into service to contend that the 1st res-respondent was "predecessor-in-mterest" to the petitioner and that the former's possession could also be taken into account. This approach found favour with the Land Tribunal. It held that the otti of 1962 amounted to a transfer by the 1st respondent, of "whatever right he had over the property" in favour of the petitioner, and that there was no residuary right left with the former. 3. The Appellate Authority however differed. It preferred to maintain the distinction between assignment of a mortgage right and creation of a sub-mortgage; in its opinion, a mortgagee could not be considered as predecessor-in-interest to a sub-mortgagee. And as regards the scope of S.4A(1)(a), this is what the Appellate Authority said:- "After the original mortgage of 1078, it is true that more than 50 years have elapsed. But what is the right of the applicant who has taken a mortgage in 1962 wherein one of the items in the mortgage is a portion of the property included in the mortgage of 1076? The applicant is in the position of a sub mortgagee only. For the first time the applicant came into possession of the property in 1962 as sub mortgagee. Under S.4A or the Explanations thereunder, there is no provision for tacking on the possession of the mortgagee by the sub mortgagee. The applicant is in the position of a sub mortgagee only. For the first time the applicant came into possession of the property in 1962 as sub mortgagee. Under S.4A or the Explanations thereunder, there is no provision for tacking on the possession of the mortgagee by the sub mortgagee. S.4A only contemplates two categories of persons who can claim rights as tenants by virtue of the deeming provision. One type is the mortgagee with possession and the other type is the lessee of such a mortgagee. The applicant in this case is not the mortgagee with possession contemplated by the Section, nor is the lessee of such a mortgagee. S.4A is not attracted at all." In the above view, the appeal was allowed and the application under S.72B was dismissed. And it is this order of the Appellate Authority that is now challenged in revision. 4. The question therefore is a short and simple one: Can a sub mortgagee who has been in possession for 8 years claim the status of a deemed tenant under S.4A (1) (a) by showing that his mortgagor was in possession for more than 42 years? As pointed out by the Appellate Authority, the language of S.4A (I) (a), by itself, does not appear to justify such an approach. The clause speaks of continuous possession by a mortgagee, and not of continuous possession by a mortgagee and another, taken together. But Explanation II permits the possession of one to be taken into the account of another under certain circumstances, for computing the period of 50 years, and to that extent the indication in clause fa) should stand modified. But is a mortgagee the "predecessor-in-interest" of a sub mortgagee, within the meaning of the Explanation? Notwithstanding the persuasive and able arguments of counsel for the petitioner, I think the answer can only be in the negative. 5. A mortgageee's right to realise the amount secured by the mortgage is itself property and he can therefore either assign it, or create a security over it. If he chooses to make an assignment, the transferee gets all his rights, and the assignor's title-the mortgage right as such-passes to the transferee. But if he chooses to create only a mortgage over his mortgage right, there is no passing of the title, though a mortgagee is sometimes said to get a derivative title to the mortgage right. If he chooses to make an assignment, the transferee gets all his rights, and the assignor's title-the mortgage right as such-passes to the transferee. But if he chooses to create only a mortgage over his mortgage right, there is no passing of the title, though a mortgagee is sometimes said to get a derivative title to the mortgage right. In relation to the sub-mortgagee, the mortgagee if the mortgagor and he will therefore have a right to pay off his debts and redeem the property, which will not be the case if an assignment of the mortgage right is made. In the latter case, the mortgagee retains no interest with him; but in the case of a sub-mortgage, some interest still remains. In other words, all the interests of a mortgagee do not pass to the transferee when a sub mortgage is created; and if that is so, it cannot be said that the interests of the two are identical, so as to hold that the one is predecessor-in-interest to the other. 6. If authority is required for this position, there are at least two by this Court. The first is the decision of Bhaskaran J., in Raghavan Vaidyan v. Parvathi Amma (1973 KLT.1024). The facts are these. While three items of paddy fields were outstanding on mortgage under Ext. Dl deed of 1075, the plaintiff demised those items to the defendant, along with some others, under an otti (Ext. P2) dated 12 41116. This deed also provided for redemption of the first three items of paddy fields by the defendant, and the amount required had also been reserved. Subsequently, the defendant got Ext. Dl mortgage released as per Ext. P1, and took possession of the paddy fields also. When the plaintiff sued for redemption, the defendant relied on S.4A (1) (a), contending that the mortgagee of Ext. D1 was bis predecessor-in-interest in view of Ext. P1 release, and that the three items of paddy fields were thus outstanding on mortgage for more than fifty years, commencing from 1075 M.E. The learned judge did not accept this contention, but held that it could have been accepted if the defendant had taken an assignment of Ext. D1 mortgage. It was observed that Ext. P1 release was obtained by the defendant as an agent of the mortgagor, as directed by him in Ext. D1 mortgage. It was observed that Ext. P1 release was obtained by the defendant as an agent of the mortgagor, as directed by him in Ext. P2 and with his money reserved for the purpose, and that in the context of Explanation II, there should be identity of interest between the two, if one was to be treated as predecessor-in-interest to the other. In Subramoina Iyer v. Lekshmikutty Amma (1976 KLT. 389), the question arose whether a mortgagee who parts with possession in favour of a sub-mortgagee can tack on the latter's possession to claim continuity for 50 years by 1170, even if he has redeemed the sub mortgage before that date. Viswanatha Iyer J., held that he could not, that there was no identity of interest between a mortgagee and a sub-mortgagee for applying Explanation II andthat "predecessor-in-interest" really means "predecessor-in-title". 7. I am in respectful agreement with the principles so formulated in the above two cases. 8. Counsel for the petitioner referred to some of the observations in the Full Bench decision of the Madras High Court in Chinnah Goundan v. Subramania Chettiar (AIR. 1959 Madras 246) to suggest that there cannot be much of a difference between an assignment of a mortgage and the creation of a sub-mortgage, I do not think the decision lays down any such rule, or even makes any such suggestion. That was a case where the sub-mortgagee had sued for enforcing his mortgage and had brought the equity of redemption of his mortgagor to sale. The owner of the property was not a party to the proceedings. Since the sale did not yield the full amount payable under the mortgage decree, he sued again for the balance and prayed for the sale of the property itself. The plaint had clearly disclosed that the suit was for the balance of the money due under the sub-mortgage, and the question therefore arose whether a sub-mortgagee could have recourse to both the remedies i. e. bring to sale the equity of redemption, and thereafter, the property itself. The Full Bench held that he could not. The two remedies, one based on the covenant and the other on the derivative title to the mortgage right, were held to be mutually exclusive, so as to impose an obligation on the sub-mortgagee to elect for one of the two. The Full Bench held that he could not. The two remedies, one based on the covenant and the other on the derivative title to the mortgage right, were held to be mutually exclusive, so as to impose an obligation on the sub-mortgagee to elect for one of the two. Their Lordships were not dealing with a statutory provision similar to the one in S.4A (1) (a); and not even a question of interpreting the term "predecessor-in-interest" had arisen. No doubt, in the course of explaining the basis of the two remedies, it has been observed that a sub-mortgagee is 'to a limited extent' an assignee of the mortgage right, and that the creation of a sub-mortgage involves transfer of the mortgagee's rights 'though not absolutely'. The qualifications, though cryptic, are eloquent in bringing; out the difference between an assignment of a right and a transfer of something less than that right. And paragraph (8) of the judgment, contrary to what is urged, makes it sufficiently clear that the creation of a sub-mortgage is not the same thing as an assignment of the mortgage right. 9. In the unreported decision in S. A. No. 3/ 75, a Full Bench of this Court has also referred to the distinction between the two. The result is that the Civil Revision Petition fails and it is dismissed, but without any order as to costs, Dismissed.