A 



MANUAL OF ZOOLOGY 



BY 



RICHARD HERTWIG 



Professor of Zoology in the^University at Munich 



SECOND AMERICAN EDITION FROM THE 

 FIFTH GERMAN EDITION 



TRANSLATED AND EDITED BY 



J. S. KINGSLEY 



Professor of Zoology in Tufts College 



NEW YORK 

 HENRY HOLT AND COMPANY 



