EYE FACET NUMBER IN DROSOPHILA MELANOGASTER. 177 



instead of using white bar-eyed flies, the red bar-eyed were used. 

 As the parents were kept in the bottles for one day, the length 

 of time the developing flies were allowed to remain at the initial 



TABLE XVII. 



EXPERIMENT 17. PART OF DEVELOPMENT AT 29. REST AT 22. 



Males. 



Females. 



temperature was reckoned from the middle of that day and not 

 from the beginning of the experiment, in order to give the 

 mean time of development at that temperature for all the eggs 



laid during that day. 



TABLE XVIII. 



EXPERIMENT 18. PART OF DEVELOPMENT AT 22. REST AT 29. RED BAR-EYE. 



Males. 



Females. 



In experiments 14 and 15 the effect of temperature is to be 

 noted early in the larval period ; in 17 and 18, which were changed 

 from 29 to 22 and from 22 to 29 respectively, the effect of 



