fk, 

 BIOLOGICAL STUDIES AND ADDRESSES. VOL I 



EVOLUTION OF 

 MAMMALIAN MOLAR TEETH 



TO AND FROM THE TRIANGULAR TYPE 



INCLUDING COLLECTED AND REVISED RESEARCHES ON 



TRITUBERCULY AND NEW SECTIONS ON THE FORMS 



AND HOMOLOGIES OF THE MOLAR TEETH IN 



THE DIFFERENT ORDERS OF MAMMALS 



BY 



HENRY FAIRFIELD OSBORN 



Sc.D., LL.D., D.Sc. 



DACOSTA PROFESSOR OF ZOOLOGY IN COLUMBIA UNIVERSITY 



CURATOR OF VERTEBRATE PALAEONTOLOGY IN THE AMERICAN MUSEUM 



OF NATURAL HISTORY 



EDITED BY 



W. K. GREGORY, M.A. 



LECTURER IN ZOOLOGY IN COLUMBIA UNIVERSITY 



JUtu llork 

 THE MACMILLAN COMPANY 



LONDON: MACMILLAN AND CO. LTD. 

 1907 



