In a late number of this journal, Mr. Hamilton makes some criticisms upon an article contributed by me to the January number, having reference to the transformations of this moth. That article was prepared having regard, as a matter of course, to the climate of this locality, and as the specimens referred to were developed in the one season, the question of variation of temperature was not under consideration. That the transformation of the pupa can be furthered or delayed by atmospheric conditions, is well established; a warm room developing the imago at an earlier period than natural, and an ice-house holding it in check over one season, to be developed when restored to the climatic influence of another. My point was, from facts ascertained by rearing in confinement, with surroundings as near natural as possible, that the period of pupation, whether early or 1ate, did not create an earlier or later development of the imago, which commonly occurred at the end of May. The history of the transformation of this moth under natural conditions, would be more satisfactory than that which results from rearing in confinement, and I regret that my town residence in winter denies me this study. That extraordinary seasons further or hinder the advent of insects, is undoubtedly true, but as a general rule their time-table is quite as exact as the migratory birds.