268 ARACHNOIDEA, 



CASE those in milk as the milk mite (Acarus lactis). It has also received 



XIV 



other names. It is the Acarus domesticus of Gervais, but not of 

 De Geer, his domesticus being a Glyciphagus, as is the Acarus 

 destructor of Schrank. The reader will not suppose that we mean 

 that every species found on cheese, or every species found on flour, 

 is this species. There is more than one that feeds on cheese, and 

 doubtless also on flour. All that we mean is that the common 

 cheese mite is found upon flour as well as on cheese, and that the 

 authors above mentioned had made two out of the same species. 



Tryoglyphus siro, slightly magnified Ditto, more highly magnified. Copied 



from Robins' figure. 



It is unnecessary to give any description of the mite. The 

 small figure will give a fair idea of its general aspect, and the 

 larger one will supply the place of a description. As to its habits 

 and mode of life, there is little to add to what every one knows. 

 It lives in almost every kind of cheese when a little decayed, and 

 especially the harder parts. The individuals gather together in 

 winter in groups or heaps in the hollows and chinks of the cheese 

 and there remain motionless. As soon as the temperature rises a 

 little, they gnaw away at the cheese, and reduce it to powder. 

 The powder is composed of similar debris to that mentioned as 

 composing the dust made by the T, entomophagus — excrement 

 having the appearance of little greyish microscopic balls; eggs, 



