THE LIFE STORY 
OF 
THE BRIMSTONE BUTTERFLY. 
By FRED Hnocx, F.1L.S. 
How one of Nature’s marvellous transformation scenes takes place, 
illustrated with a series of wonderful photographs taken by the Author. 
( NE of the very first signs of Spring is the beautiful 
* Brimstone Butterfly, which appears sometimes as 
early as February or March, but more frequently about the 
middle of April, when the Cuckoo and Nightingale arrive ; 
and we, who on bright sunny days delight to search for 
the first open Coltsfoot, are always on the look out for 
the first Brimstone out from its hybernation. What boy 
(be his age ten or forty 
years) can resist being 
drawn into the chase, on 
hearing the cry: “A Brim- 
stone! A Brimstone!” 
Let us endeavour to 
find out all we can con- 
cerning the Brimstone 
Butterfly. Here is one of 
the pale females Just ahead 
of us; it seems to be 
paying much attention to 
some of the small bushes 
on the roadside, which look 
like strpling oaks; we 
must draw nearer, but not 
so as to disturb our quarry. 
the butterfly settle, and 
Fig. 1 
There is a good deal of 
young oak, birch, willow of 
various kinds, guelder rose, 
elm and young poplar. 
The Brimstone appears to 
favour the oaks, but it is 
very fastidious in its choice 
of twigs. Now itis hoverme 
over one; a moment later, 
and it has settled with its 
wings over its back, though 
before we can get near 
enough to decide what it 
is domeg, it has flown to 
another bush. Now is the 
time to steal a march, and 
we are just in time to see 
suddenly, twist its body round 
the corner, and quickly fly off; to return again in a few 
minutes, and repeat the operation of twisting its body 
round. 
At last our eyes are opened; and we realise that 
the bush is not the oak, but the Buckthorn; the food 
plant of the larva, and the Brimstone has been 
carefully selecting the most lkely twigs on which she 
has laid a single egg; on examination of one, we find 
a long sugar loaf shaped yellowish egg, delicately ribbed 
and latticed between. These eggs hatch about the end 
of May, (sometimes earlier or. later, according to the 
weather), and become full fed in June and July, 
when the larva is about one inch long, and is of a 
dark green colour above the spiracular line, which 
is white; the whole body is banded transversely by 
narrow ribs. 
29, 
a4 
