GENETICS: W. E. CASTLE 
29 
L sc S 
FIG. 1. SIDE VIEW OF MODEL FIG. 2. EDGE VIEW OF MODEL 
Seen at right angles to figure 1. 
Showing relative positions of genes of 20 sex-linked characters of Drosophila, linear ar- 
rangement not being assumed. For significance of letters, compare Diagram I. 
