BOOK REVIEW 65 (shifting) cultivation to the relatively more advanced 'settled* cultivation, production relations in the latter have not altered significantly. Though where 'settled cultivation prevails, permanent rights in land are common' (p. 55), no market in land has emerged nor has there been any significant differentiation among the peasantry. The author attributes the stability of the agrarian structure to the constraints on private initiative and enterprise that are imposed by traditional social institutions such as the matrilineal system of inheritance, the practice of 'ultimogeniture', as well as the communal nature of land tenure (p. 141). In addition, he feels that State policy, which prevents non-tribals from acquiring land in the State, also helps preserve the traditional social structure. What the author does see in terms of change in the economy is the gradual move from shifting to more intensive methods of settled cultivation because of a rising man-land ratio and the subsequent 'inability of Jhum economy to reproduce itself (p. 144). Nair characterises this as a process of 'population induced technical change*. While this is so and private property is seen to have emerged in areas where there is settled cultivation (the author equates land under settled cultivation with that which is privately owned), traditional social relations appear to still play a dominant role. For instance, he says, 'the relapse of resettled Jhumias into shifting cultivation in certain parts of Meghalaya should be viewed against the obstinacy to change inherent in the social relations' (p. 127). What strikes a reader interested in the study of change in tribal societies is the significant absence of analysis and discussion of the major tribal groups. While the Garos and Khasis do have certain traditional social institutions in common (land tenure, matrilineal inheritance, etc.), significant differences have also emerged among them because of dissimilar historical experiences. The major section of Khasis are settled cultivators as compared to Garos among whom Jhum cultivation is predominant. The latter retain the communal character of land tenure to a greater degree. On the other hand there is greater recognition of private ownership rights to land among Khasis.1 While the present study looks at tribal households in general, it is possible that a comparison between tribal groups in the context of their varied historical experiences could have helped trace the specificities of change within the larger tribal economy. Nair attributes the slow pace of change in the economy to the constraining influence of the system of land tenure and inheritance. However, this appears more of a general statement than the result of a detailed study. It is important that communal ownership of land and the matrilineal system of inheritance are closely interwoven with the practice of shifting cultivation. Where settled cultivation has become a way of life, not only are private ownership rights to land recognised but social rules are found to be less rigid.2 Whether traditional institutions continue to impede the momentum of change , or whether