viii PREFACE 



manner in which this master organ has progressively adapted itself for 

 the effective distribution of its predominant powers. 



These volumes dealing with the evolution of the brain of primates 

 represent approximately fifteen years of preparation, collection and study. 

 They emiDody the neurological evidence based upon structural and behav- 

 ioral studies of Lemur, Tarsius, Marmoset, HowHng Monkey, Baboon, 

 Macacus, Gibbon, Orang, Chimpanzee, Gorilla and Man. In this investi- 

 gation, it has been my good fortune to have access to the unusually- com- 

 plete collection of vertebrate brains gathered under the direction of Prof. 

 George S. Huntington in Columbia University. Still more fortunate w^as 

 my privilege of studying for many years under his personal supervision. 

 Indeed, most of this work is the direct result of his inspiration, instruction 

 and guidance. Each page bears some affectionate memory of his influence, 

 and the entire effort could have no finer reward than to be, if only in some 

 small way, a pupil's tribute to his great master. 



To Prof. Henry Fairlield Osborn I am also deeply indel^ted for his 

 gracious counsel and his generosity in putting at my disposal many of the 

 valuable collections of the American Museum of Natural History. The New 

 York Zoological Garden and the New York Aquarium have both been con- 

 stant and liberal contributors of valuable material. Many fine brain speci- 

 mens, particularly of the great anthropoid apes, were presented to me by 

 the late Mr. Carl Akeley after his last African expedition. One of the most 

 valuable specimens in the collection is the brain of the young gorilla, John 

 Daniel i, an animal \\ hich lived for a relatively long time in captivity and 

 offered an exceptional opportunity for the study of its behavioral reactions 

 under the influences of domestic life. 



It gives mc especial pleasure to acknowledge my gratitude to President 

 Nicholas Murray Butler and t(^ Dean William Darrach for their interest 

 in this research and particularly for having made possible the photographic 

 reproductions. 



