Of the Wings of Infefts. 233 
feathered Moth. The Wings of many Sorts 
of Gnats are adorned with Rows of Feathers 
along their Ridges, and Borders of Feathers 
round their Edge. Some again have Hairs, 
and others Hooks, placed with the greAefl: 
Regularity and Order. All of the Scarab 
Kind have Elytra f or Cafes , into which their 
Wings are folded and preferved until they 
want to employ them. Some of thefe Cafes 
reach almoft to the Extremity of the Tail, 
as in moft Kinds of Beetles and others are 
very fhort, as in the Ear-Wig. Many of 
them are likewife extremely beautiful when 
brought before the Microfcope . 
All thefe Kinds of Wings have certain 
bony Parts or Ribs, that give them Strength, 
along the Sides of which run large Blood- 
Veffels, branching out into numberlefs Di- 
viiions, and conveying Nourifhment to the 
intermediate Parts: for tho* no Circulation 
can be difcerned in them, it being probably 
extremely flow, we can fcarce doubt that 
there muff be continually a Supply of Juices 
to the Quills, Hairs, or Briflles, wherewith 
they are armed or ornamented. 
As to Motion, Wings that are filmy move 
fafler than thofe covered with Feathers. Mr. 
Hook obferves, that in the Wings of fame 
minute Flies there are many hundreds, if 
not thoufands of Vibrations in a Second, 
and fuppofes them the fvvifteil Vibrations in. 
the 
1 
