EXP. 1.--In 1877 chrysalides of _P. Ajax_ and _Grapta Interrogationis_ (the eggs laid by females of the form _Fabricii_) were experimented upon; but the results were not satisfactory, for the reason that the author having been absent from home most of the time while the pupæ were in the ice-box, on his return found the temperature above 5°-6° R. And so far as could be told, the ice had been put in irregularly, and there might have been intervals during which no ice at all was in the box. Six chrysalides of the _Grapta_ so exposed produced unchanged _Umbrosa_, the co-form with _Fabricii_. But all chrysalides from the same lot of eggs, and not exposed to cold, also produced _Umbrosa_. Nothing was learnt, therefore, respecting this species. But chrysalides of _Ajax_, exposed at same time, did give changed butterflies to some extent. From a lot of 8, placed in the box when under twelve hours from pupation, and left for twenty-four days, there came 5 males and 3 females. Of these was 1 _Telamonides_ in markings and coloration, and all the rest were between _Marcellus_ and _Telamonides_. Two other chrysalides on ice for twenty-three days gave _Telamonides_, but 3 more exposed twenty-six days, and all one hour old when put on ice, were unchanged, producing _Marcellus_. During the same season 6 other _Ajax_ chrysalides were placed in the box, and kept at about 0°-1° R. One was one hour old, and remained for five days; 1 was one hour old, and remained for two days and three-quarters; 3 at three hours old for eight days; and 1 (age omitted), six days. All these gave unchanged butterflies of the form _Marcellus_.