CHROMOSOMES AND SEX 



377 



XO PROTENOR 



Y o A5CfM\l5 LUn. 



XY DR050PHILA 



Fig. 212. — Several types of sex-chromosome behavior in animals with heterogametic 

 males. For the sake of clearness all are shown with two pairs of autosomes. Sex-chromo- 

 somes in the female are shown disjoining in the same mitosis as in the male, though this is 

 not known to occur in all five cases. 



