PRINCIPLES OP ZOOLOGY 



7 



THE STRUCTURE, DEVELOPMENT, DISTRIBUTION, 

 AND NATURE 



OF THE 



I 



RACES OF ANIMALS, LIVING AND EXTINCT 



WITH NUMEROUS ILLUSTRATIONS. 

 PART I. 



COMPARATIVE PHYSIOLOGY. 



FOR THE USE OF SCHOOLS AND COLLEGES. 



LOUIS AGASSIZ AND A. A. GOULD, | g^O 6" - 1 



REVISED EDITION. 



BOSTON: 

 GOULD AND LINCOLN, 



59 WASHINGTON STREET. 



1 8 53. 



