i62 NATURAL HISTORY 
Houfe-martins are diftinguifhed from their congeners by having 
their legs covered with foft downy feathers down to their toes. 
They are no fongflers ; but twitter in a pretty inward foft manner 
in their nefts. During the time of breeding they are often greatly 
molefted with fleas. 
I am, &c. 
LETTER XVIL 
TO THE SAME. 
DEAR SIRj RiNGMER, near Lewes, Dec. 9, i773> 
I RECEIVED your lafl: favour juft as I was fetting out for this place; 
and am pleafed to find that my monography met with your appro- 
bation. My remarks are the refult of many years obfervation ; 
and are, I truft, true in the whole : though I do not pretend to. 
fay that they are perfectly void of miftake, or that a more nice 
obferver might not make many additions, fince fubjeds of this 
kind are inexhauftible. 
If you think my letter worthy the notice of your refpeftable 
fociety, you are at liberty to lay it before them ; and they will con- 
lider it, I hope, as it was intended, as an humble attempt to pro- 
mote a more minute inquiry into natural hiftory; into the life and 
converfation of animals. Perhaps hereafter I may be induced to 
take the houfe-fwallow under confideration ; and from that pro- 
ceed to the reft of the Britijlj hirundines. 
Though 
