I 1 1 1 1 1 1— 1 



I— I 1 1 I 1 I 1 



Fig. 15. 

 Diagram of two 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. 



h 



H 



2 



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 Fig. 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. 



