Every one must, however, choose for himself, as to taking the sentimental or the entomological view of the matter. Each probably finds its followers, and to the occasional prevalence of the more tender sentiment, are probably owing many of those stray Swallow-Tails that turn up here and there in unlikely places. The chrysalides, for rearing, may be obtained in the autumn or winter, either from entomologists resident in the localities of the butterfly, or more generally and certainly from the London or Cambridge dealers, who will send them into the country by post for a few pence each. The flight of this species is rapid and powerful, and it has a habit of soaring loftily. In this country its head quarters are in the fens of Cambridgeshire, Norfolk, and Huntingdonshire. It has been found in some abundance near Cambridge, Norwich, Yaxley, Whittlesea Mere, Burwell, and Hornsey Fens; also singly in Lancashire, at Battersea, Pulborough in Sussex, near Ashford in Kent, at Balcombe, Isle of Wight, Hampshire, near Chatham, at Southend, Essex, and on the Cliffs of the South Coast. {67} From its local character, this is of course one of the species that the collector can hardly expect to meet with, except he live in one of the districts given above as its head quarters. In these, however, it is abundant enough, and the first sight of a number of these grand insects on the wing must be enough to gladden the eye of any naturalist. This butterfly comes out first in May, and is met with from that time till August. * * * * * THE BRIMSTONE BUTTERFLY. (_Gonepteryx Rhamni._) (Plate III. fig. 2.) Though one of the commonest of our native butterflies, this, like numberless other very common things, is also one of the loveliest, both in the graceful outline of its wings, and in the lively hue that overspreads their surface; charms the more to be appreciated, as this insect is one of the few that do not wait for the full bloom of summer ere they condescend to make their appearance, but in the earliest, chill months of spring, and even in the dead winter season, the country rambler is sometimes gladdened by its gay flight; and in fact there is not one winter month that is not occasionally enlivened by this flying flower, when a day of unwonted mildness and sunshine tempts it from its winter retreat. {68} Until very recently it had always been stated by entomologists, that the Brimstone Butterfly was "double-brooded" (a term meaning that it went through _two whole cycles of existence_, from the _egg_ to the _perfect insect_, in _one year_), one brood appearing in May, and the other in the autumn.