Sex-Chromosome Maps. 



73 



others by the spacing of the loci in clusters, with intermediate 

 regions almost blank. Such regions show relatively little conformity 

 in the different species. If the cases of parallel characters are reliable, 

 they furnish more definite information, but we do not consider it 

 safe to base any detailed comparison on this ground at present. 

 The relations are easily seen by an examination of figure 16. 



D.willistoni 



D.obscura 



-glazed 



■ short 



D.simulans D.virilis 



D.melanogaster 



. .Yellow- 

 Prune - 



■ -Rubyoid' 



■ -bubble 



Crossveinless-' " " 



-■Singed- ., 



Carmine 



i Forked 



1 



, Scute - - 

 :^ Yellow. 

 ^ Prune 

 \White 



Notch 

 -Ruby 



lozenge 

 - -Vermilion 



- -Garnet 



nflated' 

 ■ Forked- 



sepia 

 Yellow: 



,Crossveinless 



Vermilion 



vesiculated 



Vermilion 



-■Forked- 



-Singed- '' 



-.magenta 

 ,- - Forked, 



■ short \ 



I 

 \ 



■ glazed wax'' 



■ ■droop 



Scute-.. 



-Yellow- - 



^cutellar 

 -Yellow 



Notch 



White 



Vermilion 

 Singed ' 



'Stubby 



stubby ? 

 -short 

 stubby? 



Figure 17. — The same maps as those shown in figure 16. but drawn to different scales in 



accordance with chromosome length. 



