FRUIT FLIES 



The two upper figures show the male (right) and female (left) of the 

 fruit fly. The six lower figures show some of its 200 and more muta- 

 tions, some of the most striking of which are shown by the wings. 

 Note the wingless individual in the lower right-hand corner, and the 

 one with asymmetrical wings just above. By their extensive studies of 

 this humble insect, Professor Morgan and his students have added vastly 

 to our knowledge of the laws of inheritance, which hold true not only for 

 lower animals, but for man himself. After Morgan, "Heredity and 

 Sex," 



By permission of the Columbia University Press. 

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