Swallowtail butterfly Swallowtail butterfly Swallowtail butterflies are large, colorful butterflies in the family Papilionidae, and include over 550 species. Though the majority are tropical, members of the family inhabit every continent except Antarctica. The family includes the largest butterflies in the world, the birdwing butterflies of the genus "Ornithoptera". Swallowtails have a number of distinctive features; for example, the papilionid caterpillar bears a repugnatorial organ called the osmeterium on its prothorax. The osmeterium normally remains hidden, but when threatened, the larva turns it outward through a transverse dorsal groove by inflating it with fluid. The forked appearance of the swallowtails' hindwings, which
Pythagorean comma cycle of perfect fifths were continued beyond 12 all the way to 53, the difference between this 53rd pitch and the starting pitch would be much smaller than the Pythagorean comma. This much smaller interval was later named Mercator's comma ("see: history of 53 equal temperament"). In George Russell's "Lydian Chromatic Concept of Tonal Organization" (1953) the half step between the Lydian Tonic and 2 in his Altered Major and Minor Auxiliary Diminished Blues scales is theoretically based on the interval of a Pythagorean comma. Pythagorean comma In musical tuning, the Pythagorean comma (or ditonic comma), named after the ancient