PRINCIPLES OF ZOOLOGY: 



TOUCHING 



THE STRUCTURE, DEVELOPMENT, DISTRIBUTION, 

 AND NATURAL ARRANGEMENT 



OF THE 



RACES OF ANIMALS, LIVING AND EXTINCT ; 



WITH NUMEROUS ILLUSTRATIONS. 



FOR THE USE OF SCHOOLS AND COLLEGES. 



PART I. 



COMPARATIVE PHYSIOLOGY. 



BY 



LOUIS AGASSIZ, 



AND 



AUGUSTUS A. GOULD. 



BOSTON: 

 GOULD, KENDALL AND LINCOLN. 



59, WASHINGTON STREET. 



1848. 



