1. The facts of the case are briefly as follows:— The 2nd respondent, second defendant in the suit Neelaveni Ammal, is the daughter of one Chelvanayaki Ammal. The first respondent the first defendant, M. Kothandarama Pillai, is the husband of Neelaveni Ammal. The case of the appellant/plaintiff is that defendants 1 and 2 agreed to sell the properties comprised in the plaint schedule to the plaintiff for Rs. 12,500 and executed a registered sale agreement on 28.4.1972, marked as Ex.A-1, and received an adva nce of Rs. 1,300 agreeing to receive the balance at the time of execution of the sale. Defendants 1 and 2 undertook to execute a sale deed in favour of the plaintiff in pursuance of the agreement within three months from 28.4.1972. The plaintiff had always been ready and willing to do his part of the contract. Defendants 3 and 4 who claimed to be the subsequent purchasers in collusion with the defendants 1 and 2 brought about two sale deeds in their favour, marked as Exs.B.1 and B-2, respectively. The plaintiff on coming to know about the unlawful conduct of the defendants 1 to 4 issued a notice on 19.5.1972 to the defendants 1 to 3 and one Sreenivasalu Naidu, the pate