NATURAL HISTORY OF SELBORNE. 255 



written me word that he once, and but once, saw these insects on a 

 vine at Weymouth in Dorsetshire ; which, it is here to be observed, 

 is a sea-port town to which the coccus might be conveyed by 

 shipping. 



As many of my readers may possibly never have heard of this 

 strange and unusual insect, I shall here transcribe a passage from 

 a natural history of Gibraltar, written by the Reverend John 

 White, late Vicar of Blackburn in Lancashire, but not yet 

 published : 



" In the year 1770 a vine, which grew on the east-side of my 

 house, and which had produced the finest crops of grapes for years 

 past, was suddenly overspread on all the woody branches with 

 large lumps of a white fibrous substance resembling spiders' webs, 

 or rather raw cotton. It was of a very clammy quality, sticking 

 fast to everything that touched it, and capable of being spun into 

 long threads. At first I suspected it to be the product of spiders, 

 but could find none. Nothing was to be seen connected with it 

 but many brown oval husky shells, which by no means looked like 

 insects but rather resembled bits of the dry bark of the vine. The 

 tree had a plentiful crop of grapes set, when this pest appeared 

 upon it; but the fruit was manifestly injured by this foul incum- 

 brance. It remained all the summer, still increasing, and loaded 

 the woody and bearing branches to a vast degree. I often pulled 

 off great quantities by handfuls ; but it was so slimy and tenacious 

 that it could by no means be cleared. The grapes never filled to 

 their natural perfection, but turned watery and vapid. Upon 

 perusing the works afterwards of M. de Reaumur, I found this 

 matter perfectly described and accounted for. Those husky shells 

 which I had observed, were no other than the female coccus, from 

 whose side this cotton-like substance exudes, and serves as a 

 covering and security for their eggs." 



To this account I think proper to add, that, though the female 

 cocci are stationary, and seldom remove from the place to which 

 they stick, yet the male is a winged insect ; and that the black dust 

 which I saw was undoubtedly the excrement of the females, which 

 is eaten by ants as well as flies. Though the utmost severity of 

 our winter did not destroy these insects, yet the attention of the 

 gardener in a summer or two has entirely relieved my vine from 

 this filthy annoyance. 



As we have remarked above that insects are often conveyed from 

 one country to another in a very unaccountable manner, I shall 



