OF SELBORNE 161 



myriads round the villages on llie Thames, darkening 

 the face of the sky as they frequent the aits of that river, 

 where they roost. They retire, the bulk of them I mean, 

 in vast flocks together about the beginning of October : 

 but have appeared of late years in a considerable flight 

 in this neighbourhood, for one day or two, as late as 

 November the tliird and sixth, after they were supposed 

 to have been gone for more than a fortnight. They 

 therefore withdraw with us the latest of any species. 

 Unless these birds are very short-lived indeed, or unless 

 they do not return to the district where they are bred, 

 they must undergo vast devastations somehow, and some- 

 where ; for the birds that return yearly bear no manner 

 of proportion to the birds that retire. 



House-martins are distinguished from tlieir congeners 

 by having their legs covered with soft downy feathers 

 down to their toes. They are no songsters ; but twitter 

 in a pretty inward soft manner in their nests. During 

 the time of breeding they are often greatly molested 

 with fleas. 



1 am, etc. 



LETTER XVII 



RlXOMER, NEAR I.r.wF.s, Dcc. 9, 1773. 



Deap Sir, 

 I received your last favour just as I Avas setting out for 

 this place ; and am pleased to find that my monography 

 met with your approbation. My remarks are the result 

 of many years' observation ; and are, I trust, true on the 

 whole : though I do not pretend to say that they are 

 perfectly void of mistake, or that a more nice observer 

 might not make many additions, since subjects of this 

 kind are inexhaustible. 

 55— F 



