Monthly Microscopical"] 
Journal, Aug. 1, 1869. J 
Scales of Butterflies. 
11 
articulation of the ribs, in transparency, in size, and in the length 
and shape of the peduncle ; and among them are found some very- 
anomalous forms, as in the plumules of the Pieridge. In that 
family, Fieris Agathina possesses an abnormal and unique form ; 
and so in the Lycsenidae, Lycsena hsetica resembles it in this 
peculiarity. 
And as in the Pieridse, so in the Lycaenidae, it is only on the 
males that these scales are found ; it is probable that this mark of 
virility may indicate the comparative vigour or age of the insects. On 
some individuals of the same species they are much more abundant 
than on others; and, again, in some species they are plentiful, and 
in others scarce ; and in some individuals of all species it is difficult 
to find them at all. On newly-caught specimens, however, they are 
most easily found. 
It is the genus Lycsena, with its neighbour Danis, which affords 
the scales now submitted to inspection in the plates. The upper- 
side of the wings of the males is generally bright blue, but at all 
events with more or less blue irrorations ; the males of certain species, 
however, are brown. The females are generally brown ; but even 
when they have blue surfaces, I have found no plumules on them ; 
while on the males which have any tinges or reflexions of blue, these 
scales are present. No species, however, the males of which are 
brown, yields these scales ; and yet it is not in these peculiar scales 
that the pigment or colour-reflexion resides. To a very eminent lepi- 
dopterist I some time since wrote, asking if he was aware of any 
other physiological difference between the blue and brown species. 
His reply was, " that he could not think tliere was any other differ- 
ence, but that it was a most interesting fact that when these males 
imitate the females in colour, they lose another male characteristic." 
Mr. Sidebotham has, with habitual industry and kindness, drawn 
figures of a large number of these scales ; and some are represented 
in the accompanying plates. These drawings are as truthful as 
beautiful ; the slides were mounted from insects in my own cabinet, 
and I believe reliance may be placed on the correctness of the 
nomenclature and habitat. 
Nos. la, 40, 42a, 46, and 50, belong to the genus Lyemna, 
47, 48, 49, 52, and 53, belong to the genus Danis, according to 
the arrangement of Doubleday, Westwood, and Hewitson, in their 
* Genera of Diurnal Lepidoptera,' the text-book of general diurnal 
lepidopterists. The under-sides of the insects of this genus are 
unlike those of Lycsena, but have a family resemblance of their own. 
In constituting this a genus, our authors say of it, " With general 
characters of Lycasna, it appears very (perhaps too) close to Lycsena" 
This is said without reference having been made to other than the 
usual tests. The scales have certainly a peculiarity of their own. 
The remarkable figures 38 to 41 cannot fail to attract atten- 
tion ; and at first sight it would be thought that they can have no 
