o /t 



GENERAL PRINCIPLES 



OF 



*3de4 



ZOOLOGY 



BY 



RICHARD HERTWIG 



Professor of Zoology and Comparative Anatomy in tke 

 University of Munich 



TRANSLATED BY 



GEORGE W. FIELD 



Associate Professor of Cellular Biology 

 in Brown University 



SECOND EDITION 



NEW YORK 

 HENRY HOLT AND COMPANY 



1897 



