11 
RECENT MICROSCOPY. 
By HENRY J. SLACK, F.G.S., Sec. R.M.S. 
T HE object of the following Paper is to select, from records 
of the microscopical work of 1871, some matters of the 
most general interest, giving preference to topics which either 
suggest inquiries many readers can easily follow, or throw light 
upon well-known questions that have not hitherto been settled. 
First, let us notice various attempts to elucidate the struc- 
ture of the scales of butterflies and of other insects, which, 
although not belonging to the Lepidoptera, are furnished with 
scales of a similar or identical character. 
Scales appear on various parts of insects besides their wings, 
and in many cases it is not difficult to show that the hairs of 
insects are similar structures to scales, both being modifica- 
tions of the skin. Insects’ wings must not be confounded with 
those of birds, though both are instruments of flight, acting 
upon the air in a similar manner. In the case of a bird, it is 
obvious that when the feathers are removed we come to a struc- 
ture of bone and muscle, and it is the skin that gives rise to 
various kinds of feathers, that have a most important part to 
play in enabling a bird to sustain and guide itself in the air. 
The wing of the insect is an extension of the skin or integu- 
ment covering the body, sufficiently hardened to bear atmo- 
spheric resistance, and strengthened by nervures that, although 
possessing none of the structure of bones, act in a mechanical 
way to give firmness and support. With insects, the scales 
and hairs are evidently related to similar appendages of higher 
creatures, but the wing feathers or scales of the insect do not 
assist flight, like those of the bird. They are an ornamental 
covering, probably of some use in protecting the membrane 
from which they spring, and on which we find them arranged 
like tiles on a roof ; but the flying power of an insect does not 
seem impaired when numbers of them are rubbed off. By their 
beautiful aspects they make, according to Mr. Wallace’s obser- 
vations, males and females mutually attractive, and they are 
frequently the means of disguises that enable their possessors 
