Transfer of Property Act (4 of 1882) , S.67— Mortgage by junior member of Marumakkathayam family - Principle of substituted Security - Applicability (i) Marumakkathayam law - Alienation. Contract Act (9 of 1872) , S.2(i)— Property held by junior member of a Marumakkathayam family is not alienable. However he enjoys certain rights in the property. If he acts without capacity by acting in excess of his rights and mortgages the property, the other members of the family are entitled to invalidate the mortgage. But until so avoided, the mortgage remains valid and binding. The avoidance of the mortgage does not deprive the mortgagee of his equity. If upon subsequent partition in the family, the mortgaged property is allotted to the mortgagor as his share the mortgagee undoubtedly will be free to enforce his right against that property notwithstanding the invalidation of the mortgage at the instance of the other members. This is because the mortgage is not void but only voidable. If a transaction is voidable only, it cannot be avoided so as to prejudice an innocent party who has for value acquired an interest in the res which is the subject-matter of the transaction. G.W. Paton, "A text-book of Jurisprudence" 3rd Edn. P. 282, Rel. on.(Para 7) As that is the position, there is no reason why the principle of substituted s....