[ 31 ] 
This Infed: is known to fubriH; chiefly on the 
fmali flies which he fiirprizes in his nets j the confe- 
quence is, that he will no more be at the trouble ot 
fpreading his web where flies cannot be expeded, 
than a fowler will lay his nets in a place where there 
is no refort of birds. 
It is believed that few of the fly tribe are found at 
any great height from the ground, as they may be 
fuppofed to prey upon ftill fmaller microfcopical in- 
fedfs, which would be the fport of the winds at any 
confiderable elevation. They are not therefore form- 
ed by nature for a high flight. 
If one may be allowed alfo to argue from 
what is obferved with regard to the fmallefl birds j 
neither the European wren nor the American hum- 
ming-bird are ever feen upon any thing higher than 
a flmib. 
Befidesthis, no fly is fcarcely ever to be found but 
where there is a good deal of light and fun-flaine ; 
confequently a wide wooden roof (be it of what ma- 
terial it may) is the mofl; improper place that the fpi- 
der can lay his fnares in. 
If fuch roof therefore is dark, though it is at the 
fame time very low, no flies will haunt it ; for a 
proof of which I may refer you to the cloiflers at 
Lincoln, or any gloomy cellar, though it may be 
above ground, and have windows which give it a cer- 
tain degree of light. 
Hence alfo fpiders webs are more common on 
whitewafli than on wainfcot, efpecially if it be painted 
of a dark colour. 
Having dwelt thus long upon the point of the 
Spanifli chefnufs being indigenous or not, I fliall 
2 now 
