EXP. 2.--In May, 1878, many chrysalides were placed in the ice-box, being from eggs laid by _Ajax_, var. _Walshii_. The youngest were but ten to fifteen minutes from pupation, and were soft; others at intervals up to twenty-four hours (the chrysalis is hard at about twelve hours); after that, each day up to eight days after pupation. All were removed from the box on the same day, 28th May. The exposure was from nineteen to five days, those chrysalides which were put on ice latest having the shortest exposure. The author wished to determine if possible whether, in order to effect any change, it was necessary that cold should be applied immediately after pupation or if one or several days might intervene between pupation and refrigeration. Inasmuch as no colour begins to show itself in the pupæ till a few hours, or at most a day or two, before the butterfly emerges, it was thought possible that cold applied shortly before that time would be quite as effective as if applied earlier and especially very soon after pupation. The result was, that more than half of the chrysalides exposed before they had hardened died: 1 exposed at ten minutes, 2 at one hour, 1 at two hours, 2 at three hours after pupation. On the other hand 1 at fifteen minutes produced a butterfly, 1 at two hours, another at twelve hours. The temperature was from 0°-1° R. most of the time, but varied somewhat each day as the ice melted. The normal chrysalis period is from eleven to fourteen days, in case the butterfly emerges the same season, but very rarely an individual will emerge several weeks after pupation. On the 14th day after taking the pupæ from the ice, 1 _Telamonides_ emerged from a chrysalis which had been placed in the ice-box three days after pupation, and was on ice sixteen days. On 19th day, 1 _Telamonides_ emerged from a pupa put on the ice twelve hours after pupation, and kept there eleven days. On 19th day, 1 _Walshii_ emerged from a pupa two hours old, and on ice eleven days. All the rest emerged _Marcellus_, unchanged, but at periods prolonged in a surprising way. 1 on 43rd day exposed 15 minutes after pupation. ” 46th ” 2 hours ” ” 53rd ” 24 hours ” ” 62nd ” 6 days ” ” 63rd ” 4 days ” ” 66th ” 7 days ” ” 77th ” 4 days ” ” 81st ” 12 hours ” ” 91st ” 5 days ” ” 96th ” 19 hours ” Five chrysalides lived through the winter, and all gave _Telamonides_ in the spring of 1879.