MODIFICATION OF COLOR. 



i 79 



During these experiments 12 per cent died in the larval stage, 23 per cent 

 in the pupal, and 65 per cent, equally divided between the sexes, emerged. 

 These were 15 per cent below the normal in size, and their development was 

 accelerated about 3.5 per cent. The hypodermal color was normal or slightly 

 darker than normal, but the dark markings were increased in size so much 

 that the imagines presented a distinct melanic appearance. On the ventral 

 surface especially the increased pigmentation was marked, the middle and 

 inner sternal spots being found in 80 per cent of the variates. The seriation 

 of these beetles into classes is as follows : 



Table SO. General color of beetles used. 



Empirical mode of parents 9 



Empirical mode of control 9 



Empirical mode in experiment... 12 



Modal deviation of parents .... 



Modal deviation of conti ol 



Modal deviation in experiment 



o 



o 

 +3 



The conditions of this experiment are nearly the same as those of experi- 

 ment 1, the resulting modifications of the elements of the color pattern, of 

 the colors themselves, and of the whole color effect being almost identical, 

 as may be seen by a comparison of tables 45 and 59. In this experiment, 

 however, the mortality was decreased, there being a total difference of 22 per 

 cent in favor of the latter. 



Experiment 9. To determine effects of an increased average deviation of temperature 

 upon the color and color pattern of L. decemlineata when applied throughout life. 



Conditions. Temperature on the average 9.5 C. above that in nature, with 

 other conditions normal. 



Apparatus. The same as in experiment 8. 



In these experiments, which were conducted in the years 1898 to 1904, 

 1,600 larvae were used, which hatched from 2,100 eggs placed in the experi- 

 ment rooms. The temperature conditions during the experiment were as 

 follows : 



Table 60. Temperature conditions. 



