Introduction
One can scarcely imagine а task more difficult than that accomplished by the author of this book. In a volume of limited size, he has undertaken to synthesize and compress subject mailer of virtually unlimited scope. In the first instance, he deals with an immense physical area, Eurasia, I he largest integrated land mass on earth, one that runs to extremes in I he variety of its land forms, its climates and the living things, both animals and plants, that exist upon it. In addition to viewing this subject in the contemporary period, he gives recognition to (hr effects of vast time spaces extending from the Cambrian age of some 500 million years ago to the present day. Ihrough the inclusion of the evolutionary story that has resulted in the present physical constitution of Eurasia, there is revealed the drama of the genesis and metamorphosis of that vast continent. AU this has been accomplished with high competence, and the result is a book of exceptional interest and value- enhanced by the fine illustrations that fill its pages.
It has required a man of Franqois Bourliere’s extensive knowledge and experience to deal with the subject in this manner. His professional qualifications, ranging from that of physician to mammalogist, are supplemented by his familiarity with geology and botany, and enriched by his awareness of the extent to which human actions affect the natural world. The significance of this humanearth relationship is at last being widely recognized, especially because of the explosive increase in human populations.
Within the story of evolutionary forces over vast reaches of time, it is of particular interest to note the great changes that have occurred in both animal and plant life in relatively recent times, namely, during the series of ice ages of the last several hundred thousand years. These changes reveal the remarkable capacity for rapid movement by both animals and plants when impelled by major climatic change, or, alternately, the extinction of numerous species simply because physical barriers on the earth’s surface prevented migrations from an intolerable to a favorable climatic environment.
The author rightly concerns himself not only with the results of man’s misuse of the land within recent history, but also with the present acute crisis brought about by him in the survival of wildlife. In this latter regard, however, he has some encouraging words to say about the restoration of the European elk and the saiga antelope, as well as the initial, limited success being gained in the protection of the European wisent and the ibex. It. is only too evident that the establishment of national parks and similar reserves for the living wild heritages of the past, whether animal or plant, is today an imperative need throughout the world.
The book is the first of a series of six that will introduce the major land areas of this earth. May they all prove as valuable and interesting.

Fairfield Osborn
President., New York Zoological Socieietyty