EYE FACET NUMBER IN DROSOPHILA MELANOGASTER. 175 



gave an average of 63 for the males and 35 for the females. 

 The males were lower and the females higher than the first 

 generation (Experiment 5) which developed at 29. 



TABLE XIII. 



THREE MORE GENERATIONS AT 29 A CONTINUATION OF THE 5.11 LINE. 



Experiments 14, 75, i$, 17, 18 (Tables XIV., XV., XVI.. 

 XVII., XVIII.). In experiments 14, 15 and 17, the effect of 

 temperature on the white bar-eye Drosophila was determined, 



TABLE XIV. 



PARENTS. EXPERIMENTS 14, 15, 17. DEVELOPED AT 27 C. 



Males. 



Females. 



and the results are fully concurrent with the results obtained 

 from the work on the red-eye. Experiment 18 gives additional 

 data for the red bar eye. 



These four experiments were made in order to determine the 

 period of development when temperature is most effective. To 

 determine this, five bottles with parents were placed at 29 and 

 the developing flies in the different bottles were allowed to pass 

 different fractions of their developmental period here. They 

 were then removed to the cold plate at 15, or to the room at 



