is TON'S SCIENCE SERIES 



ZOOLOGY 



A TEXT-BOOK FOR 



SECONDARY SCHOOLS, NORMAL SCHOOLS 

 AND COLLEGES 



BY 



THOMAS WALTON GALLOWAY, Pn.D. 



PROFESSOR OF BIOLOGY IN THE JAMES MII.I.IKIN UNIVERSITY 

 DECATUR, ILLINOIS 



Seconfc 



240 Ullustrations 



PHILADELPHIA 

 P. BLAKISTON'S SON & CO. 



IOI2 WALNUT STREET 

 1909 



