98 NATURAL HISTORY. 



which is fatal to Europeans, but never injurious to the 

 natives. 



The Cheese Mite (acarus casei) is very small, soft, 

 and has feet which terminate in points, resembling small 

 bladders. Seen through a magnifying-glass, they appear 

 like oval bodies, white, spotted with brown, and provided 

 with long hairs, which are movable. They abound in 

 old cheese, mouldy bread, etc. 



The Meal Tick (acarus farinse) resembles the fore- 

 going, but is smaller; is white, head and feet reddish. 

 These creatures live by millions in old meal ; when dried 

 fruits are kept long, they become covered with a white 

 substance resembling sugar, whih is, however, nothing 

 more than a collection of mites, that thus envelope and 

 destroy the article. Similar plagues find their way into 

 feathers, old books, etc., in short, into everything capa- 

 ble of being destroyed. 



The Aquatic Mite (hydrochna aquatica), the hand- 

 somest of the species ; is small, scarlet-colored, and may 

 be seen swimming lustily around in all stagnant waters. 



THIRD DIVISION. 

 TRUE INSECTS. HEXAPODS (SIX-FOOTED). 



The genuine Insect race differs from the Arachnidae 

 and Crustacea in the arrangement of their respiratory 

 organs (breathing, without exception, through trachea), 

 as well as in the possession of wings, and the presence 

 of six feet. Some, indeed, are without wings, and 

 might, perhaps, with propriety be classed in the orders 



