Scarce swallowtail Republic have been found to be a good indicator of relatively well preserved xerothermic grassland habitats with forest-steppe vegetation, which have no cutting history. In some years the scarce swallowtail is quite abundant. The scarce swallowtail is getting rarer as the blackthorn bushes are being cleared. The butterfly is now protected by law in the Czech Republic, Slovakia, Germany, Hungary, Luxembourg, Russia, Ukraine and Poland. It is considered rare and endangered and protected in some provinces of Austria and of indeterminate status throughout Europe. In Armenia the species demonstrates stable population trend and is evaluated as Least Concern. Though referred
Holdrian comma fact that the Ancient Greeks (or at least Boethius) believed that in the Pythagorean tuning the tone could be divided in nine commas, four of which forming the diatonic semitone and five the chromatic semitone. If all these commas are exactly of the same size, there results an octave of 5 tones + 2 diatonic semitones, 5 × 9 + 2 × 4 = 53 equal commas. Holder attributes the division of the octave in 53 equal parts to Nicolas Mercator, who would have named the 1/53 part of the octave the "Artificial Comma". Mercator's comma is a name often