''iommi.KTiS?] On the Battledore Scales of Butterflies. 73 
III. — On the Battledore Scales of Butterflies, 
By John Watson, Esq. 
Plates XXI., XXII., and XXIII. 
Some time since I communicated a series of papers on this subject to 
the ' Proceedings of the Literary and Philosophical Society of Man- 
chester ; ' but as it would seem that the subject has been noticed by 
so few other observers, I am induced to recur to it in the pages of 
the * Monthly Microscopical Journal.' 
The scales of lepidopterous insects have long been subjects of 
microscopical examination ; but it may be questioned whether suffi- 
cient notice has hitherto been taken of their peculiarities, with a 
view to the determination of the genera, species, and affinities of the 
insects, or of their systematic functions. 
The ordinary scales are more or less oval, showing from two to 
five or more dentations at the broader end, and having a short, stiff, 
pointed peduncle at the other extremity, by which they are attached 
to the membrane of the wings. These scales are flat, like those of 
fish, and show striated markings. Keferring to them in his ' Intro- 
duction to the Classification of Insects,' Westwood says, " Lyonnet 
has filled several quarto plates with representations of these scales, 
varying to almost every form, taken from the wings and body of the 
Goat Moth ; so that the suggestion of a writer that the forms of 
these scales might be used for specific characters is entitled to no 
weight." (He likewise refers to a paper upon the same subject by 
a French author, presently to be noticed.) It appears probable 
that two or more different kinds of scales, serving distinct and 
separate offices, are to be found in lepidopterous insects ; and this 
difference of function has not before been suggested. 
In some genera of the diurnal Lepidoptera, besides the ordinary 
scales, some peculiar forms exist ; and it is to these attention is now to 
be drawn, especially to those found in the genus Pieris and its con- 
geners. Examination with the microscope shows that these scales 
are not flat, like the others, but cylindrical, or bellows-shaped, and 
hollow ; they are attached to the wings by a bulb, at the end of a thin 
elastic peduncle differing in length in different species. The bulb also 
varies in size and shape ; and there is a hole or indentation to receive 
it in the membrane of the wing, larger than that for the ordinary 
scale ; and the whole apparatus has the appearance of a ball-and- 
socket joint, allowing considerable facility for motion or play. The 
scales are fixed to the wings at the broader instead of the narrower 
extremity, and there they are furnished with a fringe of ciHa or 
hairs. The scales are placed on the upper surface of the wings, 
principally on the superior ones, with their tips projecting between 
the common scales ; they are easily detached, and in removing them 
