326 On the Colowr-patterns of Butterflies. [July, 
Before leaving the subject of the dark vein scales, it may be 
desirable again to refer to the folding of the wings in the pupa state ; 
for although the pattern is not supposed to be the result of the 
plications, yet the compressed condition of every part of the wing, 
whilst in the chrysalis, must be borne in mind. The divergence of 
a portion of the vein scales to form scallops is difficult to be con- 
ceived if we regard the process as wrought in the fully expanded 
wing; but the whole scallop is a microscopic speck, and the direc- 
tion of the divergence quite indistinguishable in the pupa state. 
Yet in this state, whilst the vessels are soft and permeable, the 
scheme of the future pattern is, no doubt, fully organized, so that 
the most minute extension this way or that from the incipient vem, 
of the dark pigment bearing germs of scales, when inflated, ex- 
panded, dried and hardened in the wing of the imago, becomes a 
band, or a scallop, or a ring, according to the original construction 
and direction. 
From the vein scales, then, are supposed to arise all the darker 
markings which limit and sometimes enclose the areas occupied by 
the paler ground-tint; frequently, in fact, extending over the 
greater portion of the surface of the wing. These darker markings 
are manifestly affected by the passage of the veins, and very com- 
monly, though not always, are distinguished by an outline more or 
less sharp and distinct. 
We come now to inquire into the modifications observable in 
the paler ground-colour, proper to the scales growing on the spaces 
between the veins, and often extending over the veins themselves. 
The first and most obvious modification is the deepening or inten- 
sifying of the colour in certaim parts of the wing: thus, yellow 
becomes bright orange; white becomes yellow or scarlet; a pale 
buff becomes bright testaceous, &c. The transition is generally 
gradual, the richer being shaded off at its edges into the paler 
colour. Indeed, so characteristic of the ground-pattern is this kind 
of shading, that I propose to call the area occupied by the brighter 
and more intense hue, the “blush.” A very satisfactory example 
of the blush is seen in Gonepteryx Cleopatra. 
Belonging essentially to the membranous portions of the wing, 
the blush should not in its contour be affected by the veins, and for 
the most part it seems to be remarkably independent of them. It 
occurs in all parts of the wing, at the tip or in the disc, at the 
margin or, less frequently, near the base, often at the anal angle 
of the hind wing ; but wherever it occurs, it seems to be neither 
limited nor extended by the veins. It is of course liable, like the 
ground-colour to which it belongs, to be parted into bands or spots 
by the dark vein scales; in fact, the whole area of the blush is 
seldom seen, and more frequently than otherwise the junction of 
the blush with the pale tint, or rather the space where the junction 
