DIRECT INJURIES CAUSED BY INSECTS. &7 



Bateman subscribes ; adding as a reason for excludinaf 

 Acari from beino- concerned, tliat " they are too mi- 

 nute, and never have been seen in such numbers as to 

 be mistaken for lice." But both Acari and Pediculi 

 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 mo- 

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

 motions resemble those of lice infinitely more than do 

 the contortions of maggots. So that an Acarus would 

 be deemed a louse much sooner by an unentomological 

 observer than would a maggot. Whether Acari 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 in- 

 crease. — Millions of lice are said by Lafontaine, whom 

 Hermann calls a very exact describer, to show them- 

 selves in Plica polonica, on the third day of the dis- 

 ease*; but whether the last-mentioned author be cor- 

 rect in thinking it more probable that they are Acari'', 

 1 have not the means of judging. 



I shall now produce two instances where Acari were 

 evidently concerned. Dr. Mead, from the German 

 Ephemerides, relates the miserable case of a French 



^ Traitis de. Chirurgit, &c. Leipsig. 1792. * Mem. Jptefolog. 78. 

 TOL. I. M 



