PKEFACE TO SECOND EDITION 



In a conversation with Dr. Thompson several months 

 before his death, we discussed the advisability of the re- 

 publication of his book on Comparative Dental Anatomy 

 which had been out of print for some time. 



At Dr. Thompson's request I undertook the task of 

 preparing this new edition, feeling that there was a need 

 among dental students and teachers for a text upon this 

 subject. 



Such changes as have been found necessary in this 

 edition have the full approval of Dr. Thompson. Con- 

 flicting theories have been omitted and we have at- 

 tempted to state only proven facts. Many new and 

 original illustrations have been added, but we have tried 

 to use only those which show some interesting feature in 

 the evolution of the dental apparatus. 



A number of roentgenograms are shown which were 

 made by Dr. E. H. Skinner from specimens in my pri- 

 vate collection. 



If this volume should prove an aid to the student and 

 teacher of dentistry, it will have served its purpose. 



Martix Dewey. 



