

AMERICAN SCIENCE SERIES 





GENERAL BIOLO.GY 



BY 



WILLIAM T. SEDGWICK, PH.D. 



ASSOCIATE PROFESSOR OF BIOLOGY IN THE MASSACHUSETTS INSTITUTE OF TECHNOLOGY 



AND 



EDMUND B. WILSON, PH.D. 



PROFESSOR OF BIOLOGY IN BRYN MAWR COLLEGE 



PART I. INTRODUCTORY 



NEW YORK 

 HENRY HOLT AND COMPANY 



1886 



