204 THE CANADIAN ENTOMOLOGIST. 



placing the chrysalids on the ice at regular intervals. On my return some 

 had been exposed ten days, others but one or two, and I at once removed 

 them and waited to see the result. After six or seven days (which is the 

 usual period of the chrysalis of this species in midsummer), the tharos 

 butterflies began to emerge, and as one after another came out quite 

 unchanged, I found that the experiment with them was a failure. A week 

 later the ajax chrysalids began to give butterflies, and as they had been 

 exposed to cold some days before I left home, and while I was attending 

 to the ice box myself, the result was better. Some were fully changed, 

 var. iclamonides emerging instead of marccliiis, as would have been the case 

 in nature ; others were but partially changed, having the shape of matrelius, 

 but the broad crimson anal band of telamonides ; and others were not 

 changed at all, but emerged niarcellus. 



Later, one butterfly only emerged from the chrysalids oi pseudai-giolus^ 

 a female, and it differs curiously from the type, and from other examples 

 of the same brood which have emerged from the chrysalids not exposed 

 to cold, in that the common series of extra discal spots on under side is 

 wholly wanting, and the marginal crescents form a complete series across 

 both wings and are very large and black, so that these crescents are more 

 conspicuous than in any example I ever sa\v in the field. The other 

 chrysalids are most of them alive, but the butterflies will not appear before 

 next spring. 



The failure of the tharos to change led me to test the ice box, and I 

 found that as the ice melted the temperature rose from 45° to 55° in the 

 top of the box. Very likely, also, in my absence, the cover had some- 

 times been left raised in such a way as to admit air. 



Fortunately I had brought back from New York another batch of tharos 

 eggs, also of var. ?;/«ma, obtained in the Catskills, and the larvae from these 

 I bred in June and July, and placed the chrysalids in the ice box at 

 intervals as before, but this time at the bottom, under the ice, where I 

 found the temperature to be 33°. I had scarcely gotten the last chrysalids 

 in when I was compelled to go East again, and so lost the opportunity 

 of determining the length of time required to effect a change of form, and 

 being detained by the late railroad troubles, I did not return till twenty 

 days had passed. The same day I removed all the tin boxes from the 

 ice. They contained more or less water, and in some was enough to 

 drown the chrysalids. 



I divided the chrysalids into three lots. No. i contained all which 



