SEASONAL DIMORPHISM OF LEPIDOPTERA. 177 



This may partly explain why in the first experiment six 

 specimens showed no diminution of the spots. The one speci- 

 men of the second experiment, which also had the spots 6 and 7 

 very small without the influence of a higher degree of tempera- 

 ture, and, further, the fourth experiment, in which seven speci- 

 mens possessed quite small spots, without the employment of a 

 higher degree of temperature, show, however, that hereditary 

 individual differences also play a part in it. 



On this ground we dare not trust, without something further, 

 a result apparently so striking as that of the fifth experiment, 

 although out of 85 butterflies, which developed under a high 

 temperature, only one exhibited spots of the ordinary size, and 

 the 34 others had them smaller up to the point of disappearance. 

 Strictly speaking, the contrary experiment with cold, carried out 

 with companions of the same brood, could first satisfy us as to 

 how much is hereditary individual peculiarity and how much 

 the result of the temperature. Unfortunately experiment has 

 failed me just here. To be sure the third and fourth experiments 

 form such a pair, but the results are not so sharp as might 

 be wished. If, however, it is taken into consideration, that 

 specimens of V. iirticcc without spots 6 and 7, or with only faint 

 indications of them, are only rarely seen with us in the open, 

 the strikingly small size of these spots in 34 specimens of the 

 fifth experiment may be considered as the effect of the high 

 temperature. Further experiments are, however, required. 



VII. Effect of Heat on Hybernating Lepidopterous 

 Pup^, 1884. 



In order to determine whether a high temperature acting for 

 a longer time on pupae, which are already undergoing their 

 winter rest, can produce alterations in the colours of the perfect 

 insect, pupae of various butterflies and Sphingidae were placed in 

 an incubator with evaporating water on Jan. 10th, 1884, and 

 there subjected to a temperature fluctuating between 27° and 

 30° C. There were the following species : — 



(1) Vanessa levana 120 specimens. 



(2) Papilio podalirius 4 





(3) ,, macJiaon 4 





(4) ,, ajax 1 





(5) Thais polyxena 4 





(6) Doritis apollinus 4 





(7) Theclaruhi 2 





(8) Polyommatus amphidamas 25 





(9) Lyccena argiolus 4 





(10) „ iolas 4 





(11) Nemeohius lucina 4 





