56 



THEORY OF EVOLUTION 



dnnniD 



Vestigial Gray 



^■\^' R //J 



Long Ebony 



mim 

 ( ) 



/f^\\\ Long Gray 



i/iVr/ 



■vN 



^^ 



m \ 



Fig. 24. Cross between long ebony and gray vestigial flies. 



spring are gray with long wings. If these are 

 inbred tliey give 9 gray long, 3 gray vestigial, 

 3 ebony long, 1 ebony vestigial (figs. 24 and 



2.5). 





