VOL. XLIX, MO. 687 



NOVEMBER, 191S 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Science! } 

 Special Reference to the Factors of Evolution 



CONTENTS 



Variability and Amphimixis. Professor L. B. Walton - - - - / 

 Genetic Studies of Several Geographic Races of California Dear Mice: Dr. 



Francis B. Summer -------- _ _ , 



Shorter Articles and Discussion: Additional Evidence of Mutation in Oenothera: 

 Dr. Bradley M. Davis; The Value of Inter-annual Correlations: Dr. 



THE SCIENCE PRESS 

 LANCASTER, PA. GARRISON, N. T. 



NEW YORE: SUB-STATION 84 



