I 



QL 



AMERICAN SCIENCE SERIES ADVANCED COURSE 



ZOOLOGY 



FOR 



HIGH SCHOOLS AND COLLEGES 



BY 



A. S. PACKAKD, M.D., PH.D. 



-MEMBER OF THE NATIONAL ACADEMY OF SCIENCES; PROFESSOR OF ZOOLOGY 

 AND GEOLOGY IN BROWN UNIVERSITY 



SEVENTH EDITION, REVISED 



NEW YORK 



HENKY HOLT AND COMPANY 



1889 



