+ 



+ 



+ 



+ 



+ 



Fig. 15. 

 Diagram of trvo allelomorphic series of linked genes. In the upper 

 line the approximate location of nine, sex-linked recessive genes 

 is indicated. In the lower line the normal allelomorphic genes are 

 indicated. 



Fig. 16. 



Diagram to show crossing-over between garnet and vermilion, i.e., 



near the middle of the series shown in Fig. 15. 



Fig. 17. 



Diagram to show crossing-over between echinus and cross-veinless 



near the left end of the series. See Figr. 15. 



Fig. 18, 

 Double crossing-over between the two series of genes indicated in 

 Fig. 15. One crossing-over is between cut and tan and the other 

 between garnet and forked. 



