“11:10 a. m.—I note that the spines appear closer together at the caudal end of the body; then see that the skin has split down the back and that the light-colored head of the chrysalis is protruding. By a series of vigorous wrigglings the skin is slowly forced up to where the tip of the abdomen is attached to the button. Then comes the violent struggle which finally loosens the skin, which hangs for a moment against the ventral abdomen, then falls to the floor. The entire moult is complete in less than five minutes.”
THE CHRYSALIS
“When the chrysalis first appears it is nearly cylindrical; no dorsal depression, no ventral bulge. The head is bent forward, and the whole thing has a compact, slug-like appearance. An hour or so later the head is no longer bent, and bears two double projections, set wide apart; the wing cases are bulging and prominent; on the dorsal side, opposite the middle of the wing covers, is a U-shaped depression; there are projections on the third, fifth, sixth, and seventh abdominal segments, those on the third being the largest. At first the head, thorax and wing covers are translucent and nearly white; the abdomen is a little darker and bears a ventral bluish stripe on the fourth, fifth and sixth segments. The four pairs of dorsal protuberances are amber-colored.
“An hour later the head and thorax darken somewhat, and opaque whitish veins appear in the wing covers. Distinct black lines mark the outer borders of the fore wings, and a black V-shaped mark shows the position of the larger of the three discal spots.
“Another hour and the translucent appearance is gone, the abdomen and the dorsal thorax become much darker, the wing covers grayish tan, while the bluish ventral stripe turns gray or white.
“From this time forward the chrysalis does not change appreciably in form or color (although the latter varies greatly) until about twenty-four hours before the emergence of the butterfly, when the entire body becomes very dark.
“The average length of the chrysalis is 28 mm., and the white ventral stripe is usually the most conspicuous marking. After the butterfly has emerged the color variations of the chrysalis still persist in the empty shells, some being much darker than others.
“Not infrequently the cast skin of the larva is found attached to the anal portion of the chrysalis. This skin is black excepting the head, which is gray, and the black branching spines loom large because of the contraction of the empty skin.
“Sometimes the chrysalids turn bright yellow; these are usually infested by parasites. I have opened many of these pupae, but have never found the parasitic larva itself; the pupae and adults I have often taken, the latter being a small (2.3 mm.), green hymenopterous insect which I have not as yet had the opportunity to classify. Some ten or a dozen of these insects emerge from a small round hole, usually in the wing cover, in early August.”