LECTURE IX. 
119 
operating as a pair of additional legs. The body 
is of a thick and roundish shape 5 in some species 
nearly globular, and in others flattish. The com- 
mon Cheese-Mite or Acarus Stro of Linn^us is 
a familiar example of the genus. It proceeds from 
an egg deposited by the parent insect, and is at 
its first hatching, perfectly like the parent except 
in size, and in wanting the third pair of legs, 
which do not make their appearance till after the 
first casting of its skin. Tlie Mite is beset with 
long hairs, and if it be accurately surveyed by 
the microscope, it will be found that these hairs 
are not of a simple structure, but are bearded 
along the sides in the manner of the bristles on 
an ear of barley. 
To the genus Acarus or Mite belongs a very 
curious Insect popularly known by the name of 
the Harvest Bug, which is of a bright scarlet 
colour, and so very small as to be but just visible 
to a good eye without the assistance of a glass. 
In the middle of summer, or rather towards 
its decline, this little animal is often pecu- 
liarly troublesome by attaching itself to the skin 
of those who walk among long grass or through 
corn fields. 
