502 ON CHEESE AND BACON-HOPPERS 



upon the mind of a first beginner than upon one that possesses 

 the capability of rectifying it. 



I am led to the above remarks, by observing an error in a 

 work (the general execution of which I am very much pleased 

 with) now in course of publication. The article to which I 

 allude is in the British Cyclopaedia, Division III. on Natural 

 History, Vol. II. p. 8, " Cheese-hopper, or Cheese-mite," in 

 which the editors have confounded the larva of a dipterous 

 insect with an apterous one (Acarus lactei). The error com- 

 mences in the very heading of the article, by using the conjunc- 

 tion " or ;" had they used " and," it would have been intelligible, 

 but the name of such insect should have been the head of a 

 separate article. It then proceeds to give an interesting account 

 of the cheese-hopper only, for the greater part of the article. 

 Afterwards it says, — " Shortly after which the grubs are 

 hatched, and feed upon the cheese, causing it to decay ; the fine 

 powder which we perceive, and which is so highly prized by 

 the gourmand, being nothing else but the excrement of the 

 grubs." The second part of the above quotation relates to the 

 cheese-mites alone, as it is a well-known fact, that when a 

 cheese is infested with the hoppers there is no powder, but, on 

 the contrary, a moisture ; now a cheese that is attacked by 

 the mites is always powdery, wherever they harbour. Any 

 dairy-maid knows that if the cheese is not well pressed to 

 separate the whey entirely from the curd, it will be much more 

 liable to the attacks of the hopper-fly than if it had been pressed 

 as it ought to have been. They also call a cheese that is 

 decayed by having maggots in it, " the wet rot," in con- 

 tradistinction to the " dry rot," which the mites generally, but 

 not always, accompany. There is also a very great difference 

 in the attack of the two insects — the hoppers being always 

 found in the interior of the cheese without any visible external 

 aperture ; the mites are as constant to the exterior, and never 

 penetrate into the inside (unless there are cracks in the cheese) 

 until the outer part where they are is entirely consumed. The 

 flies that I have succeeded in rearing from the larva, both in 

 cheese and bacon, vary considerably from the one described 

 by the editors before-mentioned. But perhaps there are seve- 

 ral species, or even a family, the larvae of which possess similar 

 saltatorial powers, and feed on the same sort of food, although I 

 have met with but one species. They state, that some time after 



