TRANSITIONS IN MORPHOLOGICAL CHARACTERS 



103 



to 28°C. The individual was allowed to remain about seven hours 

 under each of these temperatures in turn. The result was a 

 retarded reproduction similar to that at first shown in the pre- 

 ceding experiment. But again there was no transition. Ex- 

 amination of table 4 will show that a considerable continuation 

 of this line of experiment upon the progeny of this individual 

 was equally negative in result. 



Quantitative control of food 



A necessarily important external factor is food. In order that 

 the general effect of high and low nutrition might be studied, 

 a number of experiments were conducted in which the quantity 

 of food supplied to each individual was controlled. Individuals 



TABLE 4 



Influence of a fluctuating temperature upon single series 



