SELECTION IN BAR-EYED RACE OF DROSOPHILA. 395 



The reverse mutation can be explained on the theory of a 

 reversible chemical reaction between two compounds one of 

 \vhich is more stable than the other. The present facts, how- 

 ever, favor an explanation on the basis of partial non-disjunction. 



LITERATURE CITED. 



Castle, W. E., Carpenter, T. W., Clark, A. H., Mast, S. O., and Barrows, W. M. 



'16 The Effect of Inbreeding, Cross Breeding and Variability of Drosophila. 



Proc. Amer. Acad. Arts. Sci., 41: 731-786. 

 Hyde, Roscoe R. 



'14 Fertility and Sterility in Drosophila ampelophila. I., Sterility in Drosophila 

 with Special Reference to a Defect in the Female and its Behavior in 

 Heredity. II., Fertility in Drosophila and its Behavior in Heredity. 

 Jour. Exp. Zool., 17: 141-212. 

 MacDowell, E. Carlton. 



'15 Bristle Inheritance in Drosophila. I., Extra Bristles. Jour. Exp. Zool., 



19: 61-98. 

 '16 The Influence of Selection on the Number of Extra Bristles in Drosophila. 



Science, N. S., 43: 177. 

 Pearl, R. 



'12 The Mode of Inheritance of Fecundity in the Domestic Fowl. Jour. Exp. 



Zool., 13: 153-268. (Gives list of other papers.) 

 Zeleny, Charles, and Mattoon, E. W. 



'15 The Effect of Selection upon the "Bar Eye" Mutant of Drosophila. 

 Jour. Exp. Zool., 19: 515-529- 



