A MANUAL OF ZOOLOGY 



BY 



RICHARD HERTWIG 



PROFESSOR OF ZOOLOGY IN THE UXI\':eRSITT AT MUNICH 



THIRD AMERICAN 

 FROM THE NINTH GERMAN EDITION 



TRANSLATED AND EDITED BY 



J. S. KINGSLEY 



PROFESSOR OF ZOOLOGY IN TUFTS COLLEGE 



NEW YORK 



HENRY HOLT AND COMPANY 



1912 



