254 THE NATURAL HISTORY 



then discovered that, under the eaves of the church, she 

 attended upon two young, which were fledged, and now 

 put out their white chins from a crevice. These re- 

 mained till the twenty-seventh, looking more alert every 

 day, and seeming to long to be on the wing. After this 

 day they were missing at once ; nor could I ever observe 

 them with their dam coursing round the church in the 

 act of learning to fly, as the first broods evidently do. 

 On the thirty-first I caused the eaves to be searched, but 

 we found in the nest only two callow, dead, stinking 

 swifts, on which a second nest had been formed. This 

 double nest was full of the black shining cases of the 

 hippoboscse hirundinis. 



The following remarks on this unusual incident are 

 obvious. The first is, that though it may be disagreeable 

 to sv/ifts to remain beyond the beginning of August, yet 

 that they can subsist longer is undeniable. The second 

 is, that this uncommon event, as it was owing to the loss 

 of the first brood, so it corroborates my former remark, 

 that swifts breed regularly but once ; since, was the con- 

 trary the case, the occurrence above could neither be new 

 nor rare. 



P.S., One swift was seen at Lyndon, in the county 

 of Rutland, in 1782, so late as the third of September. 



LETTER LHI 



As I have sometimes known you make inquiries about 

 several kinds of insects, I shall here send you an account 

 of one sort which I little expected to have found in this 

 kingdom. I had often observed that one particular 



