BLAKISTON'S SCIKNCK SKRIKS 



ZOOLOGY 



A TEXT-BOOK FOR 



SECONDARY SCHOOLS, NORMAL SCHOOLS 

 AND COLLEGES 



BY 



THOMAS WALTON GALLOWAY, PH.D. 



PROFESSOR OF BIOLOGY IN THE JAMES MILLIKIN UNIVERSITY 

 DECATUK, ILLINOIS 



Second Edition, 1Rev>ised 

 240 11 [lustrations 





PHILADELPHIA 

 P. BLAKISTON'S SON & CO. 



IOI2 WALNUT STREET 

 1909 



