180 NATURAL HISTORY OF SELBORNE. 



of motives, that of an attachment to her young, could alone occasion 

 so late a stay. I watched therefore till the 24th of August, and 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 remained 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 hippoboscce liirundinia. 



The following remarks on this unusual incident are obvious. The 

 first is, that though it may be disagreeable to swifts 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 contrary the case, the occur- 

 rence above could neither be new nor rare. 



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

 1782, so late as the third of September. 



LETTEE LIII. 



TO THE SAME. 



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 part of a vine growing on the walls of my house was 

 covered in the autumn with a black dust-like appearance, on which the 

 flies fed eagerly ; and that the shoots and leaves thus affected did not 

 thrive ; nor did the fruit ripen. To this substance I applied my 

 glasses ; but could not discover that it had anything to do with animal 

 life, as I at first expected : but, upon a closer examination behind the 

 larger boughs, we were surprised to find that they were coated over 

 with husky shells, from whose side proceeded a cotton-like substance, 

 surrounding a multitude of eggs. This curious and uncommon por- 

 duction put me upon recollecting what I have heard and read concerning 

 the coccus vitis viniferce of Linnseus, which, in the south of Europe, 

 infests many vines, and is an horrid and loathsome pest. As soon as I 

 had turned to the accounts given of this insect, I saw at once that it 

 swarmed on my vine ; and did not appear to have been at all checked 

 by the preceding winter, which had been uncommonly severe. 



Not being then at all aware that it had anything to do with England, 

 I was much inclined to think that it came from Gibraltar among the 

 many boxes and packages of plants and birds which I had formerly 

 received from thence ; and especially as the vine infested grew imme- 



