Judgment :- 1. This second appeal is directed against an appellate order of the Nagercoil District Court raising an attachment effected in execution of a decree of the Padmanabhapuram Munsiff's Court over two items of immoveable properties. The execution court overruled the objection of the legal representative of the deceased defendant that the properties were not liable to attachment; but her appeal before the District Court was successful. The legal heirs of the assignee-decree-holder at whose instance the attachment was effected have brought this second appeal against the learned District Judge's order. 2. The relevant facts of the case are as follows. The decree directed the realisation of the amounts due thereunder by sale of the hypotheca and personally from the defendant. The defendant who was a junior member of a Nair tarwad, had while the tarwad remained undivided acquired two mortgage rights over the attached properties and under the tarwad partition evidenced by Ext.1 dated 20.3.1102 these rights together with other properties were set apart to a group composed of himself and the respondent, a grand niece of his. After the division a further mortgage right over the same properties was acquired in the name of the defendant. The defendant died before the decree was satisfied and it was after some abortive attempts to realise the amounts due as per the decree by execution that the attachment in question was effected. The partition deed provides that the properties mentioned in B Schedule thereof shall be jointly enjoyed by the defendant and his grand niece and that on the death of the defendant the latter will become the absolute owner of all the B schedule items. The partition deed does not specifically refer to the three mortgage rights; but it is the properties comprised in the mortgages that are mentioned instead in the B schedule as items 4 and 5. The respondent's mother had other children besides the respondent. In Ext.1 while the defendant and the respondent took for themselves B schedule properties jointly the mother and some of her other children took the G schedule properties and the remaining children were allotted H and I schedule properties. 3. The respondent's mother had other children besides the respondent. In Ext.1 while the defendant and the respondent took for themselves B schedule properties jointly the mother and some of her other children took the G schedule properties and the remaining children were allotted H and I schedule properties. 3. The objection the respondent raised before the execution court was that the properties in B schedule belonged to a sub-tarwad composed of the defendant and the respondent and that as the former had no alienable or heritable interest in the properties they were not during his life time or thereafter liable to be proceeded against for his personal or separate debts. Both the lower courts overruled this claim. It is an impossible position that a thavazhi or a sub-tarwad as such can be formed by mere agreement of parties. It was freely conceded by the respondent's learned Counsel that Marumakkathayam law does not countenance the formation of such a unit capable of holding properties with the incidents attaching to marumakkathayam properties. Also it was so held recently by a Full Bench of this Court in Kallianikutty Amma v. Devaki Amma 1950 K.L.T. 705. On this identical ground it was that the lower courts repelled the objection that the attached properties formed sub-tarwad properties. The execution court however thought that as the original acquisitions viz., the three mortgage rights stood in the name of the defendant whatever interest the respondent derived in the properties under the partition arrangement or by the death of the defendant was subject to the liability of those properties for the debts of the defendant. This view as pointed out by the lower appellate court is to ignore the effect of the rights attached having been brought into the hatch pot at the time of the partition. Whether the two mortgages that were in existence when the partition arrangement was come to really belonged to the defendant alone, or they were tarwad assets which happened to stand in his name the effect of the arrangement was to admit the respondent to equal ownership with the defendant in those two rights as in all the other items included in the B schedule. The defendant renounced his rights in his separate properties to the extent of an half share in them in favour of the respondent. The defendant renounced his rights in his separate properties to the extent of an half share in them in favour of the respondent. The terms of partition deed are clear and unequivocal that during their life time both the defendant and the respondent shall have equal rights in the B schedule properties and that after the defendant died the respondent shall be the absolute owner of the entire (B schedule) items. It is therefore clear that on the true construction of the partition deed the defendant and the respondent took the B schedule properties as tenants-in common and that by no stretch of imagination can the respondent's half share in them be held to be liable to be proceeded against for the defendant's personal or separate debts. The lower appellate court had so construed the partition deed but its decision went differently for a different reason. 4. Before we deal with the ground of the lower appellate court's decision there are two or three other matters to be mentioned. One is that the appellant's learned Counsel conceded that though the attachment purported to be of items 4 and 5 of the B schedule as described there viz., the immovable properties covered by the mortgage what right the defendant or the respondent had over items 4 and 5 was only the mortgage interests and not the property as such. The attachment can therefore take effect only over the defendant's half share in the mortgage rights. It may also be mentioned here that the respondent's learned counsel did not contend that the third mortgage acquired after the partition should be treated differently from the two earlier mortgages. It is really an accretion to the original mortgage and one-half share in it necessarily goes to the respondent in her own right. 5. Yet another point to be disposed of before we come to the governing part of the lower appellate court's decision is that to counter the above view of the true construction or the implications of the partition deed the appellant's counsel raised an argument founded on clause six of the partition deed that the rights in all the pre-existing mortgages were kept in tact in their respective owners and that under the partition deed the owners of those mortgages had not renounced their special rights in favour of the tarwad or any individual member thereof. This we are afraid is a misreading of clause six. The tarwad had given mortgages of some of its properties and individual members had redeemed a few among such mortgages and those members were in separate enjoyment of those rights. It is only those special rights that were left untouched by the said clause and not mortgage rights pure and simple acquired by individual members. Here the first mortgage of 1078 was originally acquired by a member of the tarwad and she assigned it to a stranger. Defendant 1 bought that right. It cannot be brought under Cl. 6 which has application only to mortgages granted with respect to tarwad properties and not to mortgage rights individual members owned over properties belonging to strangers. The lower appellate court had turned down this argument when it was raised before it. 6. We have next to deal with the ground of the lower appellate court's decision that the properties are not liable to attachment. Before the present attachment was taken out the appellants or their predecessor-in¬interest had caused item 1 of the B schedule in the partition deed to be attached in execution of this decree. The respondent raised a similar objection to that attachment that the property attached was sub tarwad property. That objection was upheld by the execution court by an order dated 20.2.1121 and the decree-holders allowed that order to become final by leaving it unchallenged by an appeal. The learned judge in the court below has held that the said order precluded the appellants from agitating the question over again. He bases it on the principle underlying the rule of res judicata. In fact that was the only ground the respondent's learned counsel pressed before us to sustain the order under appeal. It is clear that the view the Munsiff took in his order dated 30.2.1121 is clearly wrong, but that by itself is no ground to hold that the order will not bind the parties. It was no doubt argued for the appellant that a patently wrong order in execution on a question of law cannot operate as res judicata with respect to a different subject matter. In the view we take as to the availability of the plea of res judicata to the respondent here we do not think it necessary to attempt to resolve that moot question in this second appeal. 7. In the view we take as to the availability of the plea of res judicata to the respondent here we do not think it necessary to attempt to resolve that moot question in this second appeal. 7. The learned judge in the court below has pointed out in his order that the appellant before him (respondent here) did not raise the plea of res judicata before the execution court and that on behalf of the respondents there it was strenuously urged that that plea should not be allowed to be permitted to be raised for the first time in the appellate court. The learned judge did not accede to that argument as it appeared to him that being a question of law it could be raised at any time. We are afraid this is a wrong exercise of the discretion vested in the appellate court. This is a case where the respondent filed her written objections to the attachment after it was effected and no reference whatever was made in it to the prior order. On the other hand what it shows is that he courted a fresh trial of the question as to the sub¬tarwad character of the properties. When the decision went against her she cannot be allowed to turn round and fall back upon the prior order. 8. A plea founded upon the rule or principle of res judicata is a plea that can be waived by a party. Rajani Kumar Mitra v. Ajmaddin Bhuyva AIR 1929 Cal. 163. A party is not entitled to go into the question of res judicata when it has not been properly raised by the pleadings. Jagadish Chandra Deo v. Gour Hari Mabator AIR 1936 P.C. 258. Decided cases even hold that a party who fails to plead res judicata as a defence is not entitled to take advantage of an evidence which happens to be on the records for a different purpose to establish such a claim. Ramprasadgiri v. Krishnanadgiri AIR 1938 Bom. 23 at P. 30. Ordinarily it is not permissible to allow a plea of res judicata to be raised for the first time in appeal. Rangayya v. Ramayya A.I.R. 1941 Mad. 815. We have already said that the objection petition did not contain any reference to this plea nor does the order show that it was taken before the execution court. Ordinarily it is not permissible to allow a plea of res judicata to be raised for the first time in appeal. Rangayya v. Ramayya A.I.R. 1941 Mad. 815. We have already said that the objection petition did not contain any reference to this plea nor does the order show that it was taken before the execution court. Before the lower appellate court it was objected that the plea should not be allowed to be raised. In the circumstances of the case and on the authorities referred to we hold that the respondent should not have been allowed to raise this plea for the first time in appeal. Accordingly we set aside the lower appellate court's decision founded on it. No doubt, we are calling to aid a technical argument but where interests of justice demand it courts have to use such arguments to defeat equally or more technical contentions. Here it is common ground that the Munsiff's prior order was manifestly wrong. 9. In the result we modify the decision of the lower appellate court and hold the attachment to be good as against one-half share in whatever rights the defendant and the respondent jointly held over items 4 and 5 of the B Schedule of Ext.1 as explained earlier in this judgment. The lower appellate court's decision releasing those items from the attachment will remain good to the extent of the respondent's original half share in them; the other half share which devolved on her consequent on the death of the defendant will be available to the appellants to be proceeded against in execution pursuant to the attachment effected. In the circumstances the case parties will bear their respective costs in this proceeding throughout in all the three courts. Modified.