Hopkinsville Kentuckian

Wonder of Metamorphosis

Evolution of the Gossamer-Winged Dragon Fly From Sluggish Pupa Is Impressive Spectacle.

Says a writer in the Scientific American: "A wonderful spectacle is presented by the sudden appearance of an insect's wing in the completion of its metamorphosis. The transformation of the grub into the butterfly, though familiar, is none the less amazing, but the evolution of the active and gossamer-winged dragon-fly, from its ugly and sluggish aquatic pupa, is still more impressive. Early on a May morning the pupa emerges from its cocoon at the bottom of a ditch, swims on its back, by paddling with its long haired paws, to the stem of an aquatic plant, and climbs up out of the water. Then, after a momentary pause, the skin suddenly bursts open and the perfect insect appears, with closely folded wings, which soon unfold and assume their final form.

"The older naturalists thought that the insect swallowed air, with which the wings were inflated. In reality the air is absorbed in the digestive organs, causing an increased blood pressure, which mechanically expands the wings. The presence of dew is also necessary, hence the first flight is always made at dawn.

This spectacle of the birth of wing may be observed in dragon-flies reared in an aquarium, the atmosphere of which should be moistened with an atomizer when the pupa rises to the surface."