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 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 3rd September.

LETTER LIII.

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 sides proceeded a cotton-like substance, surrounding a multitude of
eggs. This curious and uncommon production put me upon recollecting what
I have heard and read concerning the _coccus vitis viniferae_ of Linnaeus,
which, in the south of Europe, infests many vines, and is a 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 immediately under my
study-window, where I usually kept my specimens. True it is that I had
received nothing from thence for some years: but as insects, we know, are
conveyed from one country to another in a very unexpected manner, and
have a wonderful power of maintaining their existence till they fall into
a nidus proper for their support and increase, I cannot but suspect still
that these cocci came to me originally from Andalusia. Yet, all the
while, candour obliges me to confess that Mr. Lightfoot has written me
word that he once, and but once, saw these insects on a vine at We