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every circiimftance that does not immediately refpeit 
felf“prefervationj or lead at once to the propagation or 
fiipport of their fpecies. I am, with all refpec^l, 84c. 
letter II. 
of the SWIFT, or BLACK MARTIN. 
DEAR SIR, Selborne, Sept. 28, I 774 *- 
A S the Swift or Black Martin is the largeft of the 
Britifh hirundincs.^ fo it is undoubtedly the lateft 
comer : for I remember but one inftance of its appearing 
before the laft week in April; and in feme of our late 
frofty, harlh fprings.it has not been feen till the begin- 
ning of May. This fpecies ufually arrives in pairs.. 
The fwift, like the fand-martin, is very defe^ive m. 
architeaure, making no cruft or Ihell for its neft; but 
forming it of dry graffes and feathers, very rudely and 
inartificially put together. With all my attention to, 
thefe birds I have never been able to difcover one m the 
aa of colleaing or carrying in materials: fo that! have 
fufpeaed (fince their nefts are exaaiy the fame), that 
they fometimes ufurp upon the houfe-fparrows and ex- 
pel them, as fparrows do the houfe and fand-martin; 
well remembering t^at I have feen them ftiuabbling to- 
gether 
