Chapter I: Introduction

This volume of the evolution series of the pocket library is, like its predecessors, an expansion of a lecture which the author has frequently given before popular audiences. It differs from its immediate predecessor in that it is more loosely planned, and less obviously designed to instruct. Geologic tables and explanations have been omitted entirely; these the reader can secure from the volume in this Series (No. 47) entitled “Animals of Ancient Seas,” while something about fossils and their origin is given in the first chapter of “The Building of the Earth.” (No. 275.)

The lecturer is more fortunate than the writer in that his illustrations are more numerous; indeed, a good stereopticon lecture need be little more than a collection of beautiful and accurate slides interestingly described. However, the publishers have been generous in the number of illustrations used in these booklets, so that the difficulty is in a measure overcome.

It remains for me to acknowledge my indebtedness to the various authors and articles mentioned in the text and in notes. Dr. Lucas’ excellent and interesting book, “Animals of the Past,” has afforded in a concise form much information that otherwise could have come only from scattered technical papers. The article by Dr. Case has furnished the base for the entire first chapter, much of the material being reproduced with but the slightest changes in wording and arrangement, with the omission of some technical data. Professor Case’s position as our principal authority on Permian vertebrates gives this chapter a reliability that could not be achieved by a second-hand re-writing of material from his larger and more detailed monographs.

C. L. F.