This book was written in 1965 and slightly revised in the following year. Delays in publication have rendered some substantive parts obsolete. Yet, the formal approach and the model sketched in this essay, as well as the combined used of diachronic data and synchronic methods, seem to retain some interest. It is therefore proposed not so much as a modest stimulus for further studies of French kinship than as an equally modest contribution to anthropological and historical analyses. 

I should like to thank the following colleagues, who are not to be held responsible for my mistakes, for their generous help during the composition of this work : Professors G. C. Homans, D. Maybury-Lewis, and D. L. Oliver, Harvard University ; Professeurs C. Lévi-Strauss, Collège de France, H. Mazeaud, Faculté de Droit et Science Économique, and M. L. Wagner, Faculté des Lettres, Sorbonne ; Professeur M. Cohen, Emeritus ; M. I. Chiva, Laboratoire d'Anthropologie Sociale, Collège de France et École des Hautes Études Économiques et Sociales ; M. L. Bernot, École des Hautes Études Économiques et Sociales ; Mmes M. L. Tenèze et C. Marcel Dubois, M. H. Raulin, et M. G. H. Rivière, Musée des Arts et Traditions Populaires ; Dr. R. Needham, University of Oxford ; J. L. Verdier, Faculté des Sciences, Orsay ; Professor A. R. Diebold, Stanford University ; M. P. Menget, Université de Nanterre ; Dr. L. d'Azzevedo, Massachusetts Institute of Technology ; and Professor E. Köngäs Maranda, my wife. 

Paris, 22 VI 71