200 



COLORATION IN LEPTINOTARSA. 



and 30 per cent (3,180) emerged. In both larvse and adults the color modi- 

 fications and the order and direction of fusion or obliteration of markings 

 were the same as those that have already been described. The general results 

 derived from these experiments are represented in the curves given in text- 

 figure 16. 



Tn experiments a, b, and c, the result as expressed in text-figure 16 was a 

 shifting of the mode toward the albinic side, which was slight (to class 8.5) in 

 a, more pronounced (to class 7) in b, and extreme (to class 5) in c. In a the 



Text-figure 16 To illustrate the general results obtained in a series of twenty-one experiments 

 wherein both temperature and moisture were used in combination as stimuli. 



temperature (6 C. above the average), which alone would produce a modal 

 deviation of two or three classes toward a melanic condition, was overpow- 

 ered by the other factor of 10 per cent relative humidity below the average, or 

 it was at any rate neutralized thereby, so that the resulting imagines were 

 practically normal. In b and c the temperature had become inhibitory, so that 

 the result was a rapid fall in general coloration toward albinism. In experi- 

 ments d, e, and f much the same results were obtained. In d the temperature 

 (6 C), which alone would produce melanism, was overpowered by the more 

 highly deviating relative humidity, and albinic tendencies were produced, 

 which were further increased in e and f, where the temperatures were higher. 

 Likewise in g, h, and i the modification was albinic even at the start, and 

 increased rapidly as the temperature became inhibitory. In experiments / to u, 



