CHAPTER XV 



OTHER METHODS OF SEX-DETERMINATION 

 INVOLVING THE SEX-CHROMOSOMES 



THE determination of sex through the redistribu- 

 tion of the sex-chromosomes in the germ-cells is 

 regulated in some animals in other ways than 

 those described in the preceding chapter. 





%t 



•;>' 



; C#, 



Fig. 126. 



Separation of the two small X-ehromosomes from the autosomes in 

 Ascaris eggs, (After Geinitz.) 



The Attachment of the X-Chromosomes to Autosomes. 



The attachment of the sex-chromosomes to other chro- 

 mosomes, that is known to occur in a few forms, tends to 

 conceal the differential character of X- and Y-chromo- 



