Appendix. 119 



not warmed. In April, 1870, they all gave the Levana 

 form, with the exception of a single Porinia. 



B. About an equal number of pupae were placed in 

 the hothouse, but without any result ; for, notwithstand- 

 ing a temperature of 12 24 R., not a single butterfly 

 emerged in the course of October and November. The 

 pupae were then allowed to hibernate in an unheated 

 room, and in April and May gave nothing but Levana. 



8. Caterpillars of the second generation, found at the 

 beginning of June, 1870, pupated on I3th 15th June, 

 and gave, at the ordinary temperature, on June 29th 

 3<Dth. 7 butterflies of the Prorsa form. 



9. Pupae of the same (second) generation were placed 

 immediately after pupation on June iSth, 1870, in a 

 refrigerator (o 1 R.), and after remaining there four 

 weeks (till July 1 8th) gave, at the ordinary summer 

 temperature : 



On the 22nd of July, 2 Prorsa. 



23rd 3 

 24th 6 Porima, 4 of which were 



very similar to Levana. 

 25th I Levana, without the blue 



marginal line. 

 26th 2 Levana, also without the 



blue marginal line. 

 2nd August, 6 Porima. 



Total . . 20 



Of these 20 butterflies only 5 were of the pure Prorsa 

 form. 



10. Full grown larvae of the fourth generation, found 

 on August 20th, 1870, pupated on August 26th to Sep- 

 tember 5th. The pupae were divjded into three portions : 



A. Placed in the hothouse (12 25 R.), immediately 

 after pupation and left there till October 2Oth. Of 



