Respondents 1 and 2 in their application under 0. 1, r. 10(2), of the Code of Civil Procedure, in essence, relied upon the five following grounds for their plea that they should be added as defendants in the suit: (1)That respondent I was the lawful and legally wedded wife of respondent 3, (2) That respondent 2 was the son of respondent 3, (3) That respondents 1 and 2 should be joined as parties to the suit because the question to be adjudicated upon would seriously affect their rights and interest in the estate of respondent 3, (4)That by adding respondents 1 and 2 as parties neither a new cause of action would be introduced nor would the nature of the suit be altered, (5)That the issue to be tried in the suit, after res pondents I and 2 were added as parties, would still be the same as the case made by the appellant was that respondent 3 was interested in denying the appellant 's marriage to respondent 3 a fact which respondents I and 2 were equally interested in denying.