

ICE MELTING FROM A TWIG 



WHAT IS A BREED? Orren Lloyd- Jones 



VALUE OF NEGATIVE EUGENICS - Edwin G. Conklin 



THE MARKING FACTOR IN SUNFLOWERS 



T. D. A. Cockerell 



NATURAL SELECTION IN WAR - Roswell H. Johnson 



THE SELF-STERILITY PROBLEM E. J. Kraus 



PLANT BREEDING IN CUBA 



F. S. Earle and Wilson Popenoe 



REBUILDING THE LEGHORN 



TITLE PAGE AND INDEX TO VOL. VI 



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AMERICAN GENETIC ASSOCIATION. Waskington.D.C. 



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