THE APPARITION AND SUCCESSION OF ANIMAL 

 FORMS. 



DEDICATED TO THE MEMORY OF 

 THE EMINENT SWISS AND AMERICAN ZOOLOGIST 



LOUIS AGASSIZ, 

 THE FOUNDER OF THE MODERN SCHOOL OF AMERICAN BIOLOGY, 



AND OF 

 SIR RICHARD OWEN, 



A GREAT AND PHILOSOPHICAL NATURALIST, 



TO WHOSE TEACHING I AND VERY MANY OTHERS OWE OUR EARLIEST 



INTRODUCTION TO THE PRINCIPLE OF HOMOLOGY 



IN THE ANIMAL KINGDOM. 



