MODIFICATION OF COI.OR. 

 TabIwIS 7Q- — General color of beetles used. 



191 



Class 



2 



3 



4 



5 



6 



7 



8 



9 



10 



11 



12 



13 





P.ct. 



P.ct. 



P.ct. 



P.ct. 



F.cf. 



F.cf. 



F.cf. 



F.c/. 



P.ct. 



P.ct. 



P.ct. 



P.c^ 



Parents 









I 



2 



5 



20 



42 



18 



9 



2 



I 



Control 



. . j . . 





2 



7 



8 



17 



37 



iq 



8 



I 



I 



Experiment. . 



2 9 



39 



28 



12 



7 



2 



I 











Empirical mode of parents 9 



Empirical mode of control 9 



Empirical mode in experiment 5 



Modal deviation of parents o 



Modal deviation of control o 



Modal deviation in experiment . . — 5 



Experiment 19. — To determine the effect of a moderately diminished average relative 

 humidity upon the color and color pattern of L. decemlineata. 



Conditions. — Relative humidity on the average 8 per cent below that in 

 nature, with other conditions normal. 



Apparatus. — The same as in experiment 16. 



In this experiment, which was conducted during the years 1898 to 1904, 

 2,500 larvae, hatched from 3,160 eggs, were used. The conditions of experi- 

 mentation were as follows : 





Table 80. — Humidity 



conditions. 









Humidity— 



7 a.m. 



10 a.m. 



I p.m. 



3 p.m. 



8 p. m. 



Maxi- 

 mum. 



Mini- 

 mum. 



Aver- 

 age. 



Deviation 



from 

 normal. 



In nature 



In experiment . 



Per ct. 

 100 

 100 



Per ct. 



65 



60 



Per ct. 

 40 



Per ct. 



55 



40 



Per ct. 



100 



90 



Per ct. 

 100 

 100 



Per ct. 



43 

 33 



Per ct. 



74 

 66 



Per ct. 

 

 -8 



In the experiments of this series 17 per cent died in the larval stage, 18 per 

 cent in the pupal, and 65 per cent emerged. The larvae were modified 

 slightly, the hypodermal color becoming dull red and the dorsal abdominal 

 spots being largely reduced. The imagines were 6.5 per cent below the size 

 of the parents and of those under control. The hypodermal color was chrome 

 yellow, with frequent fusions among the darker spots on both surfaces. The 

 range of variation was large, but the general appearance was melanic, as may 

 be seen in the following table : 



Table 81. — General color of beetles used. 



Class 



5 



6 7 



8 



9 



XO 



II 



12 



13 



14 



15 



16 



.7 



18 



Parents 



Control 



Experiment. . . , 



P.ct. 

 I 

 2 



P.ct. 

 2 



7 

 I 



P.ct. 



2 



P.ct. 

 20 



17 

 2 



P.ct. 

 42 

 37 



3 



P.ct. 

 18 



15 



P.ct. 

 31 



P.ct. 

 2 



I 

 18 



P.ct. 



I 



I 



15 



p.ct. 



p.ct. 

 3 



P.ct. 

 2 



P.ct. 



I 



p.ct. 



I 



Empirical mode of parents 9 



Empirical mode of control 9 



Empirical mode in experiment, ... 11 

 14— T 



Modal deviation of parents o 



Modal deviation of control o 



Modal deviation in experiment . . -\-2 



