HIS book is not intended as an exhaustive review T of facts. Its aim is rather the presentation of a bio logical approach to the phenomena of social behaviour. This type of approach was revived by Lorenz's pioneer studies. It is characterized by emphasis on the need for renewed and careful observation of the huge variety of social phenomena occurring in nature; by emphasis on a balanced study of the three main biological problems function, causation, evolution; by emphasis on an appro priate sequence of description, qualitative analysis, quanti tative analysis; and finally by emphasis on the need for continuous re-synthesis. The character of this approach, combined with the limitations of space, have determined this book's contents. Limits of space led to the omission of a great deal of de scrip tion. Thus, Deegener's voluminous work on fhe multitude of types of animal aggregations has not been discussed. Also, the highly specialized 'states' of social insects have not been treated in detail, since there are excellent books dealing exclusively with them."

It is probably true, as the editor of these essays and studies by Ragnar Frisch points out, that the majority of economists are not well aware of the contributions made to their discipline by Frisch. This certainly does not apply, however, to econometricians. In fact, Frisch was one of the founding fathers of the Econometric Society and, for the first decade of its existence, its recognized leader in Europe. The annual European meetings were inspired by his enthusiasm, his unprecedented didactic talents and his amazingly diversified contributions. It is also clear that those members of the Swedish Academy of Sciences who selected candidates for the Nobel Memorial Prize in Economic Science, were fully aware of Ragnar Frisch's pathbreaking work when they decided to award him that famous Prize. While much of Frisch's earlier work has been published, in his later years of activity he harqly took the time to shape the results of his work in an optimal way for wider circulation. Although an impressively lucid writer, he evidently gave priority to solu tions of some of the planning problems he was involved in rather than to formulating them in the characteristically crystal-clear and well-structured expositions of earlier years. I very much welcome, therefore, Dr Long's initiative to make available to a wider public within the profession some of the few texts Frisch himself produced, probably under pressure from his immediate friends and col leagues."