

CARNEGIE INSTITUTION OF WASHINGTON, PUBLICATION No. 195 



PAPER No. 21 OF THE STATION FOR EXPERIMENTAL EVOLUTION 

 AT COLD SPRING HARBOR, NEW YORK 



FROM THE LABORATORY OF GENETICS 

 OF THE BUSSEY INSTITUTION 



Copies . 3ook 



were Tirsi issued 



FEB 181914 



I'HKSS OF GIBSON BROTH KUS. INC. 

 WASHINGTON, D. C. 



