BRIMSTONE. 51 



one. A considerable number of these survive the 

 winter in some place of concealment, and coming out 

 again in the spring form the so-called spring brood. 

 Many of these hybernators are found to be in very fair 

 condition in the spring, but in general they lack the 

 perfect freshness and bloom of those taken in autumn ; 

 the wings of those I have taken at this period are often 

 semi-transparent, from having lost feather, and fre- 

 quently are spotted and discoloured, as if by mildew ; 

 a sign probably of their owners having wintered in 

 damp lodgings 



Mr. Douglas states that they get very fat and full of 

 honey before consigning themselves to their long win- 

 ter's sleep; evidently an instinctive provision against 

 the waste of substance that must of necessity accom- 

 pany all, even the most sluggish vitality : in this respect 

 following the same instinct that leads bears, and other 

 hybernating animals, to fatten up to their utmost stretch 

 before retiring for the season. 



The eggs should be sought for in the month of May, 

 or a little earlier or later, on the buds and young shoots 

 of the two species of Buckthorn (Rhamnus Frangula 

 and JR. Catharticus). When examined with the micro- 

 scope, these are found to be very pretty objects of 

 conical form, with sculptured ribs on the sides. 



The caterpillar that results from these, when it grows 

 up, is of a fine green colour, shagreened over with black 

 points, and shading off into a paler line along the side. 

 Its shape is represented at Plate I. fig. 2. It is found 

 on the young buckthorn foliage that forms its food. 



The chrysalis is of the remarkable shape shown on 

 Plate I. fig. 1 3, green, marked with yellow. It remains 

 in this state for about twenty days, when the perfect 

 butterfly appears. 



The general colour of the male Brimstone Butterfly 

 is a clear, brilliant yellow, much like that of the Daffodil, 

 its contemporary ; and in the centre of each wing is a 

 small spot of rich orange-colour. A very beautiful 

 feature to be remarked in this butterfly is the silken 



E2 



