46 Of Flies. 
panded area of the wing, which confiffs of fevera! 
bony ribs, that gave ftrength to the filmy parts; which 
are thickly befet with innumerable fmall briftles, inter¬ 
mixed with as many dark fpots, which feem to be the 
roots of the hairs that grow on the other fide. 
Of other flies, fome of their wings are filmy, as the- 
dragon flies j others ftuck over with fhort briftles, 
as the flefti fly; others have divided wings, as the 
grey and white feather’d moths ; many forts of gnats 
wings are adorned with rows of feathers along their 
ridges, and borders of feathers round their edges; fome 
have hairs, and other hooks, placed with the greatefl: 
regularity and order. In the butterfly and fome moths, 
there are an infinite number of fmall feathers, which 
cover both the under and upper furfaces of this thin 
film, not only fhaped much like the feathers of birds, 
hut alfo variegated with the greatefl: variety of curi¬ 
ous bright and vivid colours ; which is evident to the 
naked eye, but much more entertaining when view’d 
through the microfcope ; by which we are informed, 
that thefe curious colour’d minute feathers end In quills, 
and are placed in orderly rows with great exadtnefs, 
as the holes they come from fhew when they are 
rubb’d off. 
Fig. 87. reprefents a fmall piece of a butterfly’© 
Wing; AB fhews one of thofe bony ribs that gives it 
ftrength, along whofe fides are fuppofed to branch out 
Various blood-veffels, conveying nourifhment to the in¬ 
termediate parts ; although no circulation can be dif- 
cern’d therein, we can fcarce doubt but that a con? 
tiqual fupply of juices muff be carried on to thefe mi¬ 
nute quills, hairs, and briftles; C, C, C, exhibits threa 
of thefe Angle plumes, with their quills adhering to 
franfparent membrane of the wing, in which mem- 
bran? 
