90 DIRECT INJURIES CAUSED BY INSECTS. 



species, M'hicli, from its feeding upon milk, Linne deno- 

 miiiates A. JLactis. The great author last mentioned 

 describes an insect, a native of America, under the name 

 of Pediculus Jlicinoides, which, upon the authority of 

 Rolander, he informs us, gets into the feet of people as 

 they walk, sucks their blood, oviposits^ in them, and 

 so occasions very dangerous ulcers. It A\ould be an 

 Acarus, he observes, but it has only six legs. Now 

 Herman affirms, that some species of Tromhidium (a 

 genus separated by Fabricius from Acarus) have in no 

 state more than six legs**. Others of the tribe of ^ca- 

 ridce, and the insect in question amongst the rest, may 

 be similarly circumstanced ; or those that Rolander 

 examined might have been larvae, which in this tribe 

 are usually hexapods. 



Linne appears to have been of opinion that many 

 contagious diseases are caused by Acari*^. How far he 

 "was justified in this opinion I shall not here inquire; 

 facts alone can decide the question, and observations 

 made by men acquainted with Entomology as well as 

 the science of diseases. Considerable deference and 

 attention, hovv'ever, arG certainly due to the sentiments 

 of so great a naturalist, in whom these necessary qua- 

 lilications were united in no common degree. With 

 respect to the dysentery and tlie itch, he affirms that 

 this had been manifested to his eyes. You will wish 



* It is to be hoped this new word may be admitted, as the laying of 

 eggs cannot otiierwise be expressed without a periphrasis. For the' 

 same reason its substantive Oviposilion will be emplojcd. 



'' Me7n. Aplerulogique, 19, 



" Insecta ejnsmodi niinutissima, forte Jcaros divcrsas specie! causas 

 esse diversorum morbonmi contagiosorum, ah analogia et exprrientia 

 hactenus acquisita, facili crediraus negotio. Amcen. Ac. v. 94. 



