i 843 :i,003 15,421 2,243 ll,846 



Since mutations have occurred in eight species of Drosophila 

 it seems probable that mutations may be found in all the mem- 

 bers of this genus. As to the frequency of mutations, there may 

 be individual variation. The writer's own experience would in- 

 dicate that mutations occur less frequently in busckii than in 

 ampclophila, for, during the same period in which the two 

 busckii mutations were found, a smaller number of ampelophila 

 were examined less critically and six mutations were found. 



LITERATURE CITED 



Metz, Chas. W. 



1916. Mutations in Three Species of Drosophila. Genetics, I, 591- 

 607. 



^915. The Mechanism of Men.lelian Heredity, pp. xiii -j- 262. New 

 York, Henry Holt and Co. 



Don C. Warren 



