438 



EFFECT OF TEMPERATURE UPON FACET NUMBER 



velopment and further changes in temperature had no effect on the 

 facet number thereafter. 



A second culture, allowed to develop 3 days at 27°, demonstrates 

 individual variation in rate among separate bottles. In this cul- 

 ture the effective period was passed by thirteen individuals at 27°, 



TABLE XVI. 



Experiment 59, Showing Distribution of Facet Numbers. Larvce Were Allowed to 



Complete Part Development at 27° and Were then Transferred to 15° 



for Remainder. 



before the transfer was made; and in many others the counts are 

 intermediate showing that the reaction was going on at the time of 

 the transfer from 27 to 15°. 



A control mating by the same parentage as the foregoing series 

 was reared at 27°. It shows the normal distribution of the 27° 

 stock. 



