GENETICS AND EUGENICS 



A TEXT-BOOK FOR STUDENTS OF BIOLOGY AND 



A REFERENCE BOOK FOR ANBIAL 



AND PLANT BREEDERS 



I 



BY 



W. E. CASTLE 



PROFESSOR OF ZOOLOGY IN HARVARD UNIVERSITY AND 



RESEARCH ASSOCIATE OF THE CARNEGIE 



INSTITUTION OF WASHINGTON 



CAMBRIDGE 

 HARVARD UNIVERSITY PRESS 



LONDON: HUMPHREY MILFORD 

 OxFOBD University Press 



1921 



