VOL. L, HO. 600 



DECEMBER, 1916 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOTTRNAL 

 Devoted to the Advancement of the Biological Sciences with 

 Special Reference to the Factors of Evolution 



CONTENTS 



I 



I. Experimental Intersexuality and the Sex-problem. Dr. Richard Gold- 



H. Piebald Rats and Multiple Factors. E. C. MacDowell - - - - 

 m. Some Features of Ornamentation in the Killifishes or Toothed Minnows. 



Henry W. Fowler ---------- 



tV. Shorter Articles and Discussion : Farther Remarks on the Inheritance of 

 Congenital Cataract: Dr. D. F. Jones and S. L. Fowler. The Status 

 of Fowler's Toad: H. A. Allard - -- -- -- - 



V. Index to Volume l ------ - - -- -- - 



THE SCIENCE PRESS 

 LANCASTER, PA. GARRISON, N. Y. 



NEW YORK : SUB-STATION 84 



