YOL. XLVI, NO. 544 



APRIL, 1912 



THE 



AMERICAN 

 NATURALIST 



A MONTHLY JOURNAL 

 Devoted to the Advancement of the Biological Science! with 

 Special Reference to the Factors of Evolution 



CONTENTS 



The Continuous Origin of Certain Unit Characters a 

 tologist. Dr. Henry Fairfield Osborn - 



The Relations of Paleobotany to Geology. Dr. F. H. Knowlton - 

 The Relations of Paleobotany to Botany-Phylogeny and Taxonomy. 



The Relations of Paleobotany to Botany-Ecology. Dr. , 

 m. Shorter Articles and Discussion : The Influence of Cav< 

 Pigment Development in Larvse of Amblystoma tigrinum 



THE SCIENCE PRESS 

 LANCASTER, PA. GARRISON, N. Y 



NEW YORK : SUB-STATION 84 



