Bihar Land Reforms Act (XXX of 1950)-Law for abolition of zamindaries -Validity-Necessity to provide for compensation and of public purpose-Jurisdiction of Court to enquire into validity Delegation of legislative powers-Fraud on the Constitution-Constitution of India, 1950-Constitution (First Amendment) Act, 1951- Arts. 31, 31-A, 31-B, 362, 363-Sch. VII, List II, entries 18, 36 and List Ill, entry 42-Construction-Spirit of the Constitution Right of eminent domain-"Law", "Legislature", "Public purpose", meanings of-Convent of merger-Compulsory acquisition of private property of Ruler-Acquisition of arrears of rent paying 50%-Deduction for cost of works-Legality.