CONTENTS 



The Gene 



...... < —Richard Gotdschmidt (307-324) 



Sub-human Culture Beginnings 



—A. L. Kroeber (325-342) 



Root Hairs and Growth 



— Cliff ordH. Farr (343-376) 

 Controlled Mating in Honeybees 



—Lloyd R. Watson (377-390) 

 Experiments on Longevity 



—Raymond Pearl (391-407) 



Criteria for Distinguishing Identical 

 and Fraternal Twins 



—Taku Komai (408-418) 



New Biological Books 



Morgan on Entwicklungsmechanik 

 —S. R. Detwiler and H. B. Adelmann (419-426) 



Brief Notices (427-457) 



