DIRECT INJURIES CAUSED BY INSECTS. 75 



Willan's opinion, to which, in the letter so often referred to, 

 Dr. Bateman "subscribes, adding as a reason for excluding 

 mites from being concerned, that, " they are too minute, and 

 never have been seen in such numbers as to be mistaken for 

 lice." But both vary in size, some of the former being 

 larger than some of the latter. And allowing them to be 

 ever so minute, yet when they issue in swarms, as mites from 

 a cheese, they would be very visible, were it only from their 

 motion. Besides, as they are furnished with legs, their 

 motions resemble those of lice infinitely more than do the 

 contortions of maggots. So that a mite would be deemed a 

 louse much sooner by an unentomological observer than 

 would a maggot. Whether mites have ever been seen in 

 such numbers as to be mistaken for lice, is the point in 

 question, and therefore, by itself, cannot be admitted for a 

 valid argument. Though Acarus Scabiei does not appear to 

 swarm in ordinary cases, yet this is certainly no reason why 

 other species may not do so. Where it has once made a 

 settlement, how incredibly, and in how short a space of time, 

 does the Siro or cheese-mite multiply ! Acarus destructor 

 and many other species are equally rapid in their increase. — 

 Millions of lice are said by Lafontaine, whom Hermann calls 

 a very exact describer, to show themselves in Plica polonica, 

 on the third day of the disease ^ ; but whether the last- 

 mentioned author be correct in thinking it more probable 

 that they are mites ^, I have not the means of judging. 



I shall now produce two instances where mites were evi- 

 dently concerned. Dr. Mead, from the German Ephemerides, 

 relates the miserable case of a French nobleman, from whose 

 eyes, nostrils, mouth, and urinary passage, animalcules of a 

 red colour, and excessively minute, broke forth day and 

 night, attended by the most horrible and excruciating pains, 

 and at length occasioned his death. The account farther 

 says, that they were produced from his corrupted blood. 

 This was probably a fancy originating in their red colour; 

 but the whole history, whether we consider the size and 

 colour of the animals, or the places from which they issue, is 

 inapplicable to larvce or maggots, and agrees very well with 



1 Traites de Chirurgie, 8cc. Leipsig, 1792. 2 Mem. Apterolog. 78. 



