MODIFICATION OF COLOR. 



173 



In this experiment, which extended over the years 1895 to 1903, 6,300 

 larvae of L. decemlineata were used. All were taken at random in the last 

 instar. Food, moisture, light, soil, and other conditions were kept normal. 

 The temperature records are as follows : 



Table 52. — Temperature conditions. 



Conditions— 



7 a. m. 



I p. m. 



S p. m. 



Maxi- 

 mum. 



Mini- 

 mum. 



Aver- 

 age. 



Deviation 



from 



normal. 



In nature 



In experiment. . 



19.2 



9 



30.62 

 17.109 



I7.3S9 

 10.600 



33-5 

 18.5 



13 

 5.4 



22.403 

 12.903 







-9-5 



In these experiments 64.7 per cent died in the larval stage, 25.3 per cent in 

 the pupal, and 10 per cent completed their transformation. Of these 50 per 

 cent were males and 50 per cent females. The pupal period was on an aver- 

 age 32 days, or more than three times the duration of this stage in nature; 

 while the imagines were on an average 6.2 per cent below the normal in size. 

 The hypodermal color had become lighter, being yellow. The cuticula pig- 

 ments of the dorsal side, however, were only slightly reduced, and no spots 

 were entirely absent; but fusions between the spots were not common. On 

 the ventral surface all spots were reduced in size, but none were absent. The 

 general appearance was slightly albinic, as may be seen in the following 

 sedations : 



Table 53. — General color of beetles used. 



Class 



4 



5 

 Pci. 



6 

 P.ct. 



7 

 P.ci. 



8 

 Pci. 



9 

 P.ci. 



10 

 P.ci. 



II 

 P.ci. 



12 

 P.ci. 



13 

 P.ci. 



14 

 P.ci. 





Rcf. 



Parents .... 





I 



2 



5 



20 



42 



i8 



9 



2 



I 





Control 







2 



7 



10 



23 



30 



16 



6 



5 



I 



Kxperiment. 



I 



2 



7 



9 



36 



20 



15 



8 



I 



I 





Empirical mode of parents 9 



Empirical mode of control 10 



Empirical mode in experiment. . . 8 



Modal deviation of parents o 



Modal deviation of control + i 



Modal deviation in experiment . — i 



Experiment 6. — To determine the effects of a large decrease in the average temperature 

 upon the color and color pattern of L. decemlineata. 



Conditions. — Temperature on the average 134° C. below that in nature, 

 with other conditions normal. 



Apparatus. — The same as in experiments 4 and 5. 



In this experiment, which extended over the years 1897 to 1903, 3,000 larvae 

 taken at random in the last instar were used. The temperature records are 

 as follows : 



