170 



three weeks after emerging from chrysalis, and soon after dy- 

 ing ; and the last brood of the year hibernates, the females not 

 to be impregnated till the next spring. 



The number of moults is invariably four, and the most 

 marked changes in appearance of the larvae occur at the first 

 and third moults. With the third, come in the long curved 

 horns, and at the fourth they double in length. These horns 

 are present in the stages preceding the third moult, but are 

 shorter and straighter at the second moult, and mere stubs at 

 the first. The whole round of changes from the laying of the 

 egg to the appearance of the butterfly is rapid, and surprisingly 

 so in hot weather. The females readily lay eggs in confine- 

 ment, either upon the growing plant or plants cut and standing 

 in water. I find recorded in my journal that 29 Aug. 1868, I 

 found a larva of D. arcMppus on morning glory (Convolvu- 

 lus), which I had quite forgotten. I suppose it was feeding 

 on this plant, but I cannot now assert the fact. It remains to 

 be verified. 



I had concluded in previous years that this species must be 

 many-brooded, from the larvae which I had bred at difi'erent 

 months, and outside observations, but in 1878 I undertook to 

 breed in successive generations from early spring to the end of 

 the season, and I give the result. 



The first brood of larvae came from eggs laid 2 May. They 

 hatched on the 7th, and began to suspend on the 20th, and the 

 butterflies to appear on the 30th of May. Whole period 28 

 days. But on 21 May fresh butterflies were seen about the 

 gardens, and these must have come from eggs laid about the 

 middle of April. 



The second brood of larvae proceeded from eggs laid 1 

 June. I saw the female ovipositing, caught her, and con- 

 fined her in a bag over the plant, obtaining thus several eggs. 

 She was certainly not a hibernator, being nearly perfect in 

 wing, and I believed could have been one from the butterflies 

 seen flying on 21 May. The eggs hatched 5 June. On the 

 20th, four larvse made chrysalis, and their butterflies emerged 

 25 June. Whole period 25 days. 



The third brood of larvae proceeded from eggs laid 29-30 



