260 THE NATURAL HISTORY [LETT. 



aud 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 Wey- 

 mouth 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 Eeverend 

 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 pro- 

 duct 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 mani- 

 festly injured by this foul incumbrance. 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 per- 

 fectly described and accounted for. Those husky shells, which 

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

 sides 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, 



