OF THE HUMAN SKIN. 



35 



hundredth to one-fiftieth of an inch in lensrth. 

 Our figure here saves U8 any minute description 

 of this parasitic animal. The true pimple mite 

 was found by Henle and Gustav Simon, in 1842, 

 almost simultaneously, and independently of each 



other. They are found generally and most abun- 

 dantly in the glands of the skin which secrete the 

 grease, either opening on the surface, or into a 

 follicle, from which the hair springs. They are 

 of very frequent occurrence, it even being as- 

 serted that no one is free from them, and are dis- 

 covered in the sebaceous glands of the face, chin, 

 nose, and forehead, by pressing out the contents 

 of the gland, and adding a drop of colored oil to 

 it on the glass slide of the microscope. • They 



