PREFACE
One afternoon in June, 1876, three Princeton undergraduates were lying under the trees on the canal bank, making a languid pretence of preparing for an examination. Suddenly, one of the trio remarked: “I have been reading an old magazine article which describes a fossil-collecting expedition in the West; why can’t we get up something of the kind?” The others replied, as with one voice, “We can; let’s do it.” This seemingly idle talk was, for Osborn and myself, a momentous one, for it completely changed the careers which, as we then believed, had been mapped out for us. The random suggestion led directly to the first of the Princeton palæontological expeditions, that of 1877, which took us to the “Bad Lands” of the Bridger region in southwestern Wyoming. The fascination of discovering and exhuming with our own hands the remains of the curious creatures which once inhabited North America, but became extinct ages ago, has proved an enduring delight. It was the wish to extend something of this fascinating interest to a wider circle, that occasioned the preparation of this book.
The western portion of North America has preserved a marvellous series of records of the successive assemblages of animals which once dwelt in this continent, and in southernmost South America an almost equally complete record was made of the strange animals of that region. For the last half-century, or more, many workers have coöperated to bring this long-vanished world to light and to decipher and interpret the wonderful story of mammalian development in the western hemisphere. The task of making this history intelligible, not to say interesting, to the layman, has been one of formidable difficulty, for it is recorded in the successive modifications of the bones and teeth, and without some knowledge of osteology, these records are in an unknown tongue. To meet this need, [Chapter III] gives a sketch of the mammalian skeleton and dentition, which the reader may use as the schoolboy uses a vocabulary to translate his Latin exercise, referring to it from time to time, as may be necessary to make clear the descriptions of the various mammalian groups. Technical terms have been avoided as far as possible, but, unfortunately, it is not practicable to dispense with them altogether. The appended glossary will, it is hoped, minimize the inconvenience.
No one who has not examined it, can form any conception of the enormous mass and variety of material, illustrating the history of American mammals, which has already been gathered into the various museums. A full account of this material would require many volumes, and one of the chief problems in the preparation of this book has been that of making a proper selection of the most instructive and illuminating portions of the long and complicated story. Indeed, so rapid is the uninterrupted course of discovery, that parts of the text became antiquated while in the press and had to be rewritten. As first prepared, the work proved to be far too long and it was necessary to excise several chapters, for it seemed better to cover less ground than to make the entire history hurried and superficial. The plan of treatment adopted involves a considerable amount of repetition, but this is perhaps not a disadvantage, since the same facts are considered from different points of view.
The facts which are here brought together have been ascertained by many workers, and I have borrowed with the greatest freedom from my fellow labourers in the field of palæontology. As every compiler of a manual finds, it is not feasible to attribute the proper credit to each discoverer. Huxley has so well explained the situation in the preface to his “Anatomy of Vertebrated Animals,” that I may be permitted to borrow his words: “I have intentionally refrained from burdening the text with references; and, therefore, the reader, while he is justly entitled to hold me responsible for any errors he may detect, will do well to give me no credit for what may seem original, unless his knowledge is sufficient to render him a competent judge on that head.”
A book of this character is obviously not the proper place for polemical discussions of disputed questions. Whenever, therefore, the views expressed differ widely from those maintained by other palæontologists, I have attempted no more than to state, as fairly as I could, the alternative interpretations and my own choice between them. Any other course was forbidden by the limitations of space.
It is a pleasure to give expression to my sincere sense of gratitude to the many friends who have helped me in an unusually laborious undertaking. Professor Osborn and Dr. Matthew have placed at my disposal the wonderful treasures of the American Museum of Natural History in New York and in the most liberal manner have supplied me with photographs and specimens for drawings, as well as with information regarding important discoveries which have not yet been published. Dr. W. J. Holland, Director of the Carnegie Museum in Pittsburgh, has likewise generously provided many photographs from the noble collection under his charge, kindly permitting the use of material still undescribed. To Professor Charles Schuchert, of Yale University, I am also indebted for several photographs.
The figures of existing animals are almost all from photographs taken in the New York and London zoölogical gardens, and I desire to thank Director Hornaday, of the Bronx Park, and Mr. Peacock, of the London garden, for the very kind manner in which they have procured these illustrations for my use. The photographs have been modified by painting out the backgrounds of cages, houses, and the like, so as to give a less artificial appearance to the surroundings.
To my colleagues at Princeton I am under great obligations for much valuable counsel and assistance. Professor Gilbert van Ingen has prepared the maps and diagrams and Dr. W. J. Sinclair has devoted much labour and care to the illustrations and has also read the proofs. Both of these friends, as also Professors C. H. Smyth and E. G. Conklin and Drs. Farr and McComas, have read various parts of the manuscript and made many helpful suggestions in dealing with the problems of treatment and presentation.
For thirteen years past I have been engaged in the study of the great collections of fossil mammals, gathered in Patagonia by the lamented Mr. Hatcher and his colleague, Mr. Peterson, now of the Carnegie Museum. This work made it necessary for me to visit the museums of the Argentine Republic, which I did in 1901, and was there received with the greatest courtesy and kindness by Dr. F. Moreno, Director, and Dr. Santiago Roth, of the La Plata Museum, and Dr. F. Ameghino, subsequently Director of the National Museum at Buenos Aires. To all of these gentlemen the chapters on the ancient life of South America are much indebted, especially to Dr. Ameghino, whose untimely death was a great loss to science. It is earnestly to be hoped that the heroic story of his scientific career may soon be given to the world.
Finally, I desire to thank Mr. Horsfall for the infinite pains and care which he has expended upon the illustrations for the work, to which so very large a part of its value is due.
While the book is primarily intended for the lay reader, I cannot but hope that it may also be of service to many zoölogists, who have been unable to keep abreast of the flood of palæontological discovery and yet wish to learn something of its more significant results. How far I have succeeded in a most difficult task must be left to the judgment of such readers.
Princeton, N.J.,
June 1, 1913.