The study is concerned in the first place with an investigation of evidence for clan exogamy during the period of the Brahmanas, an the allied question of relationship-terminology. In the second place it deals with an elucidation of the complex problem of the Vratyas. An intermediary chapter is devoted to a description of the social and functional groups. Finally, a discussion of the available evidence for 'sapinda' restrictions is added. With regard to clan exogamy the word 'Aril in the Rgveda is of particular significance. 'Jana' and 'jami in the Brahmanas have also been found to be of similar importance in as such as the former signifies the marriage- able exogamous group and the latter the non-marriageable group. In the context of relationship-terminology the words 'agredidhisu' (the woman wooed before) 'didhistrpatil (the husband of 'agredidhisu') 'parivitta' (the unmarried elder brother) 'parivividana' (the younger brother married while the elder brother remains a bachelor) 'anujavara' (the posthumous son, or the younger brother of inferior status) 'bhrarvya' (the brother-in-law) and 'sajata' (fellow-clansman), are analysed. Amon the social and functional groups the distinction between those of the 'Taksan' and the 'Rathakgra' has be-n noticed. In dealing with the problem of the 'Vratyast', firstly former contributions in this field have be n reviewed in detail. Secondly, previous suggestions in connection with the etymologioal explanation of the word Vratyal have been considered. Thirdly, it has been pointed out that the 'Viatya' book of the Atharvaveda is, in all probability, compiled from fragments of a lost Brahmana text. Fourthly, the references to the 'Vratyas' in the Tandya and Jaiminiya have been duly noted and inter-pretations hitherto proposed, scrutinised. Lastly, the conolusion is arrived at, that the 'Vratyas were non-Brahmanical Aryans, possibly similar to the Ksatriyas, and having alien ritual practices. In conclusion it has been conjectured that the passage in the Satapatha bearing on 'Sapiada' restrictions ex-presses diapproval of the marriage-practice to which it refers.