456 THE NATURAL HISTORY 



structor, too frequently found in our collections of 

 insects and dried plants, where it does much mischief; 

 Acarus Farince, so abundant in stale flour, and Acarus 

 Siro, which not unfrequently swarms to such an extent 

 in old cheese, that its numbers give it quite an ani- 

 mated appearance. Many species are parasitic on 

 different animals man himself, not excepted, and 

 most notorious among his Mitey assailants are the 

 Harvest Bob (Leptus Antumnalis), and the Itch Mite 

 (Acarus Scabiei), for the attacks of which, however, 

 frequent applications of soap and water may be pre- 

 scribed, as a probable remedy in the former case and, 

 a not improbable preventative in the latter. Dogs 

 and horses are subject to the attacks of the Dog-tick 

 (Ixodes Ricinus\ which, indeed, occasionally fixes its 

 barbed rostrum in the human skin also ; other forms 

 are met with on various birds, and not the least re- 

 markable of these is the Sparrow Mite, one sex of 

 which displays an enormous pair of lobster-like claws. 

 Philodromus Limacuin may often be seen rapidly 

 coursing over the slimy bodies of more than one large 

 species of slug, and we have repeatedly seen it run in 

 and out of the respiratory orifice of Arion ater, even 

 insects, as we have already stated, have parasitic mites 

 appropriated to them. Gamtnasus Coleoptratorum is 

 the pest of beetles and humble bees, Leptus Phalangii 

 of the common shepherd spider, and (omitting many 

 others) Uropoda vegetans infests several species of 

 beetles. 



Occasionally a specimen of the common Dor (Geo- 

 trupes stercorarius) may be met with oddly disfigured 

 by masses of minute shining roundish bodies, each of 

 which, on examination, is found to be attached to the 

 underside of the beetle by a slender footstalk. On 

 further and closer examination, it will be seen that 

 these curious objects, although apparently growing 

 like tiny fungi out of the integument on which they 

 are clustered, are, strangely enough, furnished with 



