152 



HEREDITY AND SEX 



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

 and 84 males without a spot. The authors give no 

 explanation of their results — but they use the re- 



FiG. 77. — To left, in 1, is male of Euschistus variolarius, to right male of 

 E. servus. 2 and 3 show eight F2 males; 4 shows seven F2 males from 

 another mating. 



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- 



