JOSEPH KRAFKA, JR. 



431 



the length of the developmental period and the number of facets are 

 correlated up to the point where the time-temperature relations for 

 metamorphosis begin to fail. 



This leads to the question; Is the number of facets dependent upon 

 the length of the immature stage? 



TABLE xrv. 



Experiment 6. Unseleded Bar Stock. Larvce Subjected to 30° for First Part oj 

 Development; Remainder at 15°. 



Control stocks. 



In the previous experiments it is obvious that there is a certain de- 

 gree of correlation between the facet number and the length of the 

 egg-larval-pupal period. Are these two phenomena directly depend- 

 ent or are they separately affected by a third common factor? Ex- 

 periment 6 was designed for another purpose but it supplies data here. 



In Table XIV is given the distribution of facet counts in Experiment 

 6 in which the successive bottles, made up by changing the same par- 



