PREFACE. 



This "Review of the Primates" is the result of a casual suggestion 

 of my friend Frank M. Chapman, Esq., that I should "write a book 

 on Monkeys." The magnitude of the task — to compel all the described 

 forms of the Primates to present themselves in their representatives 

 for critical examination and comparison — was thoroughly appreciated, 

 and also it was equally well understood that no Institution in the 

 world contained a collection of these animals sufficiently large to permit 

 a work like the present to be successfully completed by its aid alone. 

 For over a century the Primates have been a subject of careful study 

 by Naturalists of all lands, some most eminent Zoologists having 

 devoted their investigations to them almost exclusively, and con- 

 sequently the types of the many species were scattered throughout 

 the various Museums of the world. To examine and compare these 

 important examples was a necessity, for without a thorough knowledge 

 of their characteristics no satisfactory progress toward the solution 

 of their proper scientific standing could be reached. With representa- 

 tives of the Primates, either from the eastern or western hemispheres, 

 the Museums of the United States were but poorly provided, and a reli- 

 ance for the material to prosecute the work was therefore to be 

 placed upon the collections contained in European Museums and 

 Zoological Gardens, and also in those of Eastern lands. Consequently 

 the Author was obliged to visit all these various Institutions and study 

 their collections. Twice were the Museums of England and the 

 Continent visited, and many months passed each time examining the 

 collections, and during a journey around the world, the Museums and 

 Gardens of the far East were also visited and their collections care- 

 fully studied. The Author has seen and taken a description of nearly 

 all the types of the Primates extant in the world to-day, and there is 

 not a collection of these animals of any importance existing at the 

 present time with which he is not familiar. 



The results of five years' continuous study are therefore embodied 

 in this work, and the conclusions given, no matter how they may dis- 

 agree at times with the opinions expressed by other laborers in the 

 same field, have in every case been reached only after careful and 

 patient investigation. 



Even with the collections of the world at one's service, material 

 in numerous genera is still greatly lacking; and in some of these, 



