THEORY OF EVOLUTION 



49 



amfflip 

 (nnmiD ^-■^^^ 



Vestigial 



f^ 



c 



Z) 



Long 



c 



D 



(rmmiD 



Gametes or F, 



C ) .(Illinil]) Eggs 



' X ' 



( ) 



cnTTTTTlD 



3 



C 



( ) 



cnTTT TTT D 



aTTTTTTTD 



ammiD 



Fig. 19. Diagram illustrating a cross between a fly (Dro- 

 sophila ampelophila) with long wings and a mutant fly with 

 vestigial wings. 



