VOL. XLIX, HO. 578 



FEBRUARY, 1915 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 DeTOted to the Advancement of the Biological Science! with 

 Special Reference to the Factors of Evolution 



CONTENTS 



Data on a Peculiar Mendelian Ratio in Drosophila ampelophila : Joseph Lief 

 Shorter Articles and Discussion : Selection, Sngar-beets and Thrips: Professor 

 W. E. Castlk. A Note on Multiple Allelomorphs in Mice: C. C. Little 

 On the Time of Segregation of Genetic Factors in Plants: John Belling 1 

 . Notes and Literature : Repulsion in Wheat : F. L. Enoledow. The Determina- 

 tion of the Best Value of the Coupling Ratio from a Given Set of Data : F. L. 



THE SCIENCE PRESS 

 LANCASTER, PA. GARRISON, N. * 



NEW YORK: SUB-STATION 84 



