VOL. X1IV, NO. 519 



MARCH, 1810 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Sciences with 

 Special Reference to the Factors of Evolution 



CONTENTS 



I. The Imperfection of Dominance and I 



B. DAVENPORT 



H. Experimental Evidence on the Effectiv 



III. The Artificial Production of the Parthenogenetic and Sexual P 



Life Cycle of Hydatina senta. A. FRANKLIN SHTJLL . 



IV. The Significance of the Courtship and Secondary Sexual Charac 



neads. Professor THOS. H. MONTGOMERY, Jr. . 



V. Notes and Literature : Notes on Ichthyology, President David Staj 



A New Catalogue of Hemipterous Insects, Professor T. D. A. Co. 



PRESS 



LANCASTER, PA. GARRISON, 



NEW YORK: SUB-STATION 84 



