£0 , Of Flies. 
From either fide of the probofcis, within the mouthy 
grow two fmail horns K K, which were hairy and final!* 
in this figure, but of another Fiape, and bigger in pro¬ 
portion in fig. 83. where they are marked G G, which 
two are generally called, the antennae, or horns of infedts*. 
Mfr Derharn imagines them to be obfolutely neceflary tcy 
the fearching out and finding their way 5 , as their eyes 
are immoveable ; fo- that no time' is required for their 
turning them to objedts ; there is no neceflky that the 
retina, or optick nerve,, fhould occafionally be brought 
nearer to, or removed farther from- the cornea, as it is in 
other animals ; but their cornea amd optick nerve being 
always at the fame diFance, and fitted only to- lee diFant 
objedts, they would be infenfible of, and apt to run their 
heads again!! bodies very near them, were they not 
afliFed by their feelers r and that this, rather than wiping 
the eyes, as feme have imagined,, is the particular ufe of 
the feelers, and is apparent from the fiefh fly, and many 
other infedts, which have their antennae fo fhort and 
Freight,, as not to be capable of being bent unto, or ex¬ 
tended over the eyes. 
The middle part of this fly was cafed with a firm coat 
©f armour, the upper part of which was thickly befet 
with conical briftles, pointing backwards ; from its under 
part fprang fix legs, three of which- are apparent in the 
figure at M, N,. O ; they were all of the fame Fruchire, 
being covered with an hairy fihell, and compofed of eight 
joints, to the laft of which grew the foies and claws be¬ 
fore deferibed in pag. 40. From the upper part of the 
trunk grew the two wings, which are deferibed pag. 45 ; 
the hinder part of his body was of a moft curious fhining 
blue, and exadtly like polifhed Feel, brought £0 that 
colpur by nealing. 
The 
j Dirham's Fhy, Theo, p« 3,7 z% 
