THE CANADIAN ENTOMOLOGIST, 239 



the original 122 chrysalids (several having died without yielding the 

 imago), 28 chrysalids which are likely to go over the winter. In the 

 experiments recited in But. N. A. as made with chrysalids of ajax in the 

 summer of 187 1, of several broods of telamonides the percentage of 

 butterflies which emerged the same season varied from fifty to sixty, a few 

 dying in chrysalis and the rest over-wintering. In 1870 the proportion 

 of emerging butterflies was larger, but 28 is not an unreasonable number 

 to overwinter out of 122. I conclude, therefore, that the butterflies which 

 have so far emerged this season would naturally have done so, and that 

 the effect of cold has not been to precipitate the emerging of any which 

 would have slept till next spring. And as all which would naturally 

 have emerged this season would have taken the form marcellus, the cold 

 has completely changed a large part of these from marcellus to telam- 

 onides, and probably such were from the chrysalids which were subjected 

 to severest cold. The intermediate examples have also changed, but not 

 completely, owing to the lesser degree of cold applied, as before 

 explained ; and finally, it seems probable that several chrysalids 

 experienced cold sufficient to retard their emerging and to stunt their 

 growth, but not enough to decidedly change their form. These are the 

 marcellus. As to the duration of the chrysalis period, extreme confusion 

 has been produced, so that the emerging, instead of taking place at 14 

 days after the cold was lessened or withdrawn, as might have been 

 expected, has been protracted through more than two months. In the case 

 of napi, as related by Dr. Weismann, where the chrysalids were subjected 

 to cold for three months and then brought into the green-house, the 

 butterflies began to appear in 15 days (or about their natural period), and 

 all that emerged that year did so in the next seven days. In every case 

 the reversion to the winter form was complete; and those chrysalids of the 

 lot which over-wintered all gave the same form in the spring. This it is 

 probable the over-wintering chrysalids of ajax will do, — that is, they will 

 give telamonides in the spring, and had the degree of cold applied been 

 equal and constant the reversion would probably have been complete. 

 Telamonides must be regarded as the primary form of the species. What 

 the position of Walsh ii may be further experiments will perhaps 

 determine. 



I append a table showing the dates of emergence of these butterflies : 

 20th August . 1 male Telamonides. 



2 1 st " . . 1 " 2 females " 



22nd " t " «« 



