The effect of cold suddenly applied to the chrysalids of butterflies at the moment of pupation is often to produce remarkable changes in the markings. The spots upon the wings of butterflies emerging from chrysalids thus treated are frequently rendered more or less indistinct and blurred. The dark markings are intensified in color and enlarged; the pale markings are also in some cases ascertained to experience enlargement. Many of the strange and really beautiful aberrations known to collectors have no doubt been produced by the action of frost which has occurred at the season when the larva was pupating. The species believed by the writer to be most prolific in aberrations are species which pupate early in the spring from caterpillars which have hibernated or which pupate late in the autumn. Some are species found at considerable altitudes above sea-level, where late frosts and early frosts are apt to occur. A number of very beautiful experiments upon the effect of cold upon the color of butterflies have been made in recent years, and some very curious phenomena have been observed. The writer has in his collection a considerable number of strikingly aberrant specimens which emerged from chrysalids treated to a sudden artificial lowering of the temperature at the critical period of pupation. SUBFAMILY LIBYTHEINÆ (THE SNOUT-BUTTERFLIES) "What more felicitie can fall to creature Than to enjoy delight with libertie, And to be Lord of all the workes of Nature, To raigne in th' aire from th' earth to highest skie, To feed on flowres and weeds of glorious feature, To take whatever thing doth please the eie?" SPENSER. _Butterfly._--The butterflies of this family are very readily distinguished from all others by their long projecting palpi, and by the fact that the males have four feet adapted to walking, while the females have six, in which respect they approach the Erycinidæ. Only one genus is represented in our faunal region, the genus _Libythea_. Genus LIBYTHEA, Fabricius (The Snout-butterflies) [Illustration FIG. 124.--Neuration of the genus _Libythea_.]