This butterfly, which was known, to the earliest English authors as the "Saffron" or "Spotted Saffron," has always, no doubt, been erratic and uncertain in its appearance in this country, sometimes becoming increasingly abundant for three, four, or even five years in succession, and then scarce or entirely absent for similar periods. The most recent years of plenty, or when it was fairly common, were 1877, "the great Edusa year," 1892, 1893, 1894, 1895, 1899, 1900, and 1902. In some of these years the Pale Clouded Yellow was also common. In some of the warmer countries that this butterfly inhabits it has certainly three, and possibly four, broods in the year. It is therefore conceivable that at times its increase in numbers may become very great in some particular area. At such times swarms of the surplus butterfly population set out to seek fresh fields and pastures new. Some portion of these flights reach our country from time to time, and this probably always occurs in the spring of the year. The weather conditions being favourable, the offspring of the visitors put in a welcome appearance in the autumn, and not only gladden the heart of the entomologist, but add a charm to the countryside which every one can appreciate. The butterfly has probably occurred, at some time or other, in almost every county in England and Wales, Ireland and Scotland, extending even to the Orkney Islands (1877). Its home appears to be in North Africa and South Europe, whence it spreads over the greater part of Europe and Western Asia. NOTE.--According to Kirby, this butterfly should be called _Eurymus hyale_, Linn., and the Pale Clouded Yellow be known as _Eurymus kirbyi_, Lewis. The Brimstone (_Gonepteryx rhamni_). This butterfly (Plate 26) has the tips of the fore wings sharply pointed, and there is a rather acute angle about the middle of the outer margin of the hind wings. The colour of the male is bright sulphur yellow, with a central orange spot on each wing, that on the hind wings usually the largest; there is also a rusty dot at the outer end of the upper veins and along the front margin of the fore wings towards the tip. The female is greenish yellow, and is marked similarly to the male. In both sexes the horns (_antennæ_) are reddish, and the long silky hair on the thorax is a noticeable character. It is probably this insect to which the name "butter-coloured fly," contracted into butterfly, was first given; anyway, it is the only species to which the name applies so well.