1 52 



HEREDITY AND SEX 



107 males with a spot (developed to different degrees), 

 and Si males without a spot. The authors give no 

 explanation of their results --but they use the re- 



I'm. 77. — To left, in 1, is male of Euschistus variolarius, to right male of 

 E. semis. 2 and 3 show eight F 2 males; 4 shows seven F 2 males from 

 another mating. (After Foot and Strobell.) 



suits to discredit some of the explanations, that rest 

 on the assumption that the chromosomes are the chief 

 factors in Mendelian heredity. I venture, neverthe- 

 less, to suggest the explanation shown on the accom- 



