The Journal of 



HEREDITY 



^ montkly puhlmtioyi dewkdtof/ant^reedim 

 Animal J jreedinmndEmemcs 



JUNE, 1917 



THE BIOLOGY OF TWINS 



SIGNS OF INTELLIGENCE 



BREEDING SOUTHERN GRAPES 



THE CELIBACY OF TEACHERS 



BRAINS AND SOCIAL STATUS 



URBAN STERILIZATION ^ 



DEGENERATE PLANTS 



AN OFFICE-HOLDING FAMILY 



ARITHMETICAL ABILITIES 



A LEMON BUD VARIATION 



HOW BEES RECOGNIZE EACH OTHER 



BODY AND MIND 



THE ESSENCE OF MENDELISM 



ORGAN OF THE 



AMERICAN GENETIC ASSOCIATION 



\ArASHINGTON ' D.G. 



Jrintedfor Qircutaiiopt amovi^ 'JKembers only 



