(172^) 
Tools wherewith they are able to fix themlelves to the 
Polifhed Giafs, and fo to run up. 
I have alfo cut ofF the Corfjea of the Head of thefe 
Flies, and have obferved that it was befet with very ma* 
ny faiali Hairs, which were placed not upon the Eyes, 
but between them. 
* Further, I have^taken the Matter that fills up the Cor- 
ma out of if, to judge of it by the Help of the^ Magni- 
fying Glafs, and that the rather, becaufe I could never 
before fatisfy my felf about it, viz, to what Purpofe 
this Stuff was made 5 and I did conclude, that jhis Mat- 
ter was confiding of a .Subftance like unto a Thread. 
When I had fpread a little afunderjthe mentioned Mat- 
ter, that I might obferve it with more Attention, than 
I had yet done before ; I faw, that all this Stuff, which 
I had judged to be a Thread, was very near altogether 
of the fame Length, and that one End was fomewhat 
thicker than the other, and roundiih on the thicker 
End. 
By thefe accurate Obfervations, and near Confidera- 
tions, which I often repeated one after the other,I did a(^ 
fare my felf, that this great Number of fmall Parts, 
which I faw there, was each of them a Nerve of an Eye, 
and that the thick and round End of it had been placed 
in the Hollownefs of th^Cornea : In fliort,as many Sights 
as are in the Cornea^ fo many there is of Nerves. 
The Reafon why One End of the Nerves of the Eyes 
that goeth inwards towards the Head, is thinner, as I 
havefaid before, muft neceflarily be, becaufe the Cornea 
has a roundiih Bulkinefs, and therefore the Sinews muft 
be the thinner, the farther they go in ; for the room 
grows lefs than it is, by the Ilollownefs of the Cornea^ 
and who doth know whether, that Part where the Op- 
tick Nerves do end, be not the Brain ? which muft be in- 
quired after, 
r 
