Page:Popular Science Monthly Volume 49.djvu/290

276 of the twelve districts into which the western coast strip is divided, some account of the customs and character of the Eskimos, and a historical sketch of the explorations and administration of Europeans in Greenland. His descriptive matter is frequently enlivened by anecdotes, and the text is illustrated by reproductions of many photographic views of persons and places.

materials furnished by Prof. Wright and other explorers, Prof. Upham has prepared descriptions of the plants and the animals of Greenland and of the inland ice sheet. He also devotes a chapter to tracing the continental changes of level of the Pleistocene period. With this material as a basis, he proceeds to discuss the causes of the ice age, giving the theories that have been put forth to account for the great extension of the ice, and explaining the difference of opinion among glacialists as to whether there were one or more epochs of glaciation. The authors of this book hold to the theory that the ice sheets were due to extensive uplifts of the land forming plateaus which received snow throughout the year. In another chapter the successive stages of the ice age are traced as revealed by their marginal moraines and other deposits. In conclusion. Prof. Wright summarizes the chief facts relating to Greenland's mantle of ice, and to the life of its inhabitants, who seem to be admirably adapted to their surroundings and happy in them.



is presented from a point of view somewhat different from the ordinary in a book which Prof. Williams, of Yale University, has just published. The author says that while there are no end of books on evolution, and modern biologists seem content to assume that some theory of evolution is true, and although the sociologist, the moralist, and the theologian are basing their theories about man on the "working hypothesis" of the naturalist, as if "law and gospel," it seems to have escaped serious attention that we have open for study a genuine record of the actual evolution of organisms, extending from near the beginning of life up to the present time. The geologist does not ask what is the theory of evolution, but what are the facts of evolution. The book is intended simply as an introduction to an already broad field, which is rapidly widening. The history of organisms is first taken up and treated quite fully. The next two chapters consist of a history of the making of the geological time scale, and a general consideration of its divisions. The naming and the fossils of stratified rocks, the nature of fossils and their geographical distribution next occupy attention. What is a species? What is an organism? and What is the origin of species? are the elementary but important questions answered in the next three chapters. The principles of natural history, classification, and the types of construction in the animal kingdom, occupy Chapters XI and XII. Phylogenesis in classification, the acquirement of characters of generic or higher rank, what is evolved in evolution, the modification of generic characters, and the plasticity and permanency of characters in the history of organisms, bring us to the eighteenth chapter, which takes up the cephalopoda, to illustrate the rate of morphological differentiation in a genetic series. In Chapter XIX the ammonids are studied in a similar manner to illustrate the progressive modification of an extrinsic character. The last two chapters—one on the laws of evolution, as emphasized by a study of the geological history of organisms, and finally the philosophical conclusions regarding the causes determining the course of evolution, are in the nature of a general summary of the whole subject.