About 24 hours after the chrysalis turned black, the butterfly begins to emerge (or eclose) from the chrysalis. The chrysalis splits open, and the butterfly’s head, feet, and wings emerge. The butterfly holds on tightly to the chrysalis, pulls out its abdomen, and hangs from the now-empty chrysalis casing.
When it first emerges, the butterfly’s wings are small and crumpled, and its abdomen is very large. The butterfly’s first job is to pump fluid from its abdomen into its wings. If you watch for about 30 minutes, you will see the wings unfold and grow larger, as the butterfly pumps them full of fluid. You may even see a drop or two of pink liquid fall from the wings.
After the wings are fully pumped up, the butterfly hangs for another one to two hours, and gently flaps its wings, to dry them. It is only then that it is ready to fly.
This video shows a timelapse of some butterflies emerging from their chrysalises. (A timelaspe is a video made from a series of photos taken at various intervals, which speeds up the action.) Included in the video is a close-up of a butterfly pumping fluid from its abdomen to its wings.