LECTURE IX. 119 



operating as a pair of additional legs. The body 

 is of a thick and roundish shape ; in some specfes 

 nearly globular, and in others flattish. The com- 

 mon Cheese-Mite or Acarus Siro of Linnaeus 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. The 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. 



