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. serous. 2 and 3 show eight F2 males ; 4 shows seven F2 males frona 

 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- 



